Why are there no marine birds?

Walking by the lake and watching the ducks the other day a thought struck me; there are lots of aquatic birds but all remain at least somewhat terrestrial, nesting on land.

Why is it that no birds have taken the evolutionary route of the dolphins and whales and returned to the sea?

Is there something in avian biology that means this is not possible?

Apart from one isolated group of birds in Australia (i.e., mound nesters found in Australia that use external heat for incubation - see link), all birds incubate their eggs (see link). All species that returned from land to sea have retained their reproductive cycle (marine mammals still give live birth and suckle their young) and still rely on air for oxygen intake. Extrapolating this mammalian evolution to birds would result in a creature that returns to sea, with all ties to land cut off, but that still has to incubate their eggs under water. As they would still rely on air, this is not very feasible as they would need to go up often to breath. This would leave the eggs vulnerable to predation. Even worse, it would leave the eggs at the mercy of a relatively cold ocean cooling them down quickly. Incubation means that the eggs are pretty much kept at body temperature which is difficult in the sea regardless of breathing parents. In all, while there may be certain benefits of underwater life for birds, it will require some drastic evolutionary changes in terms of the reproductive cycle. A more parsimonious way of colonizing the sea is to go back to land once and a while to lay eggs, incubate them, and raise the young until they are sea-worthy, like penguins do as @MattDMo mentioned.

This is a quite old question (more than 3 years now), and chances are OP will never read this. However, I'd like to give my contribution:

The issue here is not if birds incubate or not their eggs (see the other answer). Even if we suppose that no bird incubate its eggs, that is, that all birds lay their eggs and just walk away and that the eggs develop normally at cold temperatures, even so there could be no "marine bird" the way OP asks, like a dolphin. And the answer is in the egg itself.

The amniotic egg

Birds, which are a group of dinosaurs, together with the other reptiles and the mammals show an outstanding evolutionary innovation: the amniotic egg.

The amniotic egg allowed our Amniota ancestor to leave the water and to complete the whole reproductive cycle on land. It was a great evolutionary achievement, which allowed the tetrapod "conquest" of dry land.

An amniotic egg (tortoise)

However, there is a catch: that amniotic egg, which allowed our ancestors to be independent of water for reproduction, cannot be laid on water. Due to several reasons, mainly the (lack of) gas exchange through its shell, the embryo will not develop if the amniotic egg is laid on water.

That's why marine turtles have to leave the water to lay eggs, slowly crawling on the sand in a very exhausting task which will some time later put their very babies in danger. It would be preferable laying the eggs in the water, where they are already… but they can't.

Evolutionary solution: Viviparity

So, how could some mammals take that evolutionary route? Because (most of) mammals don't lay amniotic eggs: they developed viviparity instead. And that viviparity allowed mammals such as whales and dolphins to spend their whole life in the water, never coming to the land.

A very interesting proof of this evolutionary explanation is the case of the ichthysaurs. This extinct group of marine reptiles spent all their reproductive cycle in the water, never returning to the land. How is that possible with an amniotic egg? The answer is that ichthyosaurs didn't lay eggs: just as mammals, they were viviparous. That viviparity allowed them to be truly aquatic.

Artistic representation of an ichthyosaur with its viviparous embryo

This now famous image (Motani et al., 2014) shows a very rare - and tragic, since they died - fossil, a pelvis of a Chaohusaurus mother with three embryos, one of them clearly visible:

So, we can only speculate that, the day some bird develop viviparity (or radical changes in the amniotic egg structure and physiology), then we can have a truly marine bird.

Source: Motani, R., Jiang, D., Tintori, A., Rieppel, O. and Chen, G. (2014). Terrestrial Origin of Viviparity in Mesozoic Marine Reptiles Indicated by Early Triassic Embryonic Fossils. PLoS ONE, 9(2), p.e88640.

39 List Of Marine Biology Courses in The University

This page is for those who are interested in Marine Biology and will like to know the courses or classes they will attend before they can become a Marine Biologist. The simple truth is, there is no easy way you can get comprehensive information on classes needed for Marine Biology because of the lack of a universal curriculum.

Every institution offering Marine Biology have their own curriculum. To know all Marine Biology major classes means you will visit each of these institutions and take a look at their course outlines which is impossible.

What I have listed on this page are Marine Biology courses/classes you may attend and there is no guarantee that all the listed Marine Biology courses will be available in the school you have chosen.

Nevertheless, you may likely attend 80% of Marine Biology major classes listed here. A marine biology program can qualify you for many careers related to research, oceanography and biology, as well as those related to marine resources as viewed from an economic, sociological or information technology perspective.

These are Marine Biology Courses

  1. Aquatic Animal Physiology and Reproduction
  2. Arctic Marine Vertebrate Ecology
  3. Biology and Culture of Aquatic Organisms
  4. Biology of Fishes
  5. Biology of Shellfishes
  6. Climatic Extremes
  7. Comparative Anatomy and Physiology of Marine Organisms
  8. Coral Reef Ecosystems
  9. Currents and Tides
  10. Diseases of Aquatic Organisms
  11. Ecological Modeling
  12. Ecology and Conservation of Marine Birds and Mammals
  13. Estuaries
  14. Fisheries Ecology
  15. Fisheries Oceanography
  16. Genetics and Molecular Ecology
  17. Geology and the Ocean
  18. Hydrothermal Systems: An Interdisciplinary View
  19. Invertebrate Zoology
  20. Life in the Ocean’s Depth
  21. Life in the Polar Oceans
  22. Marine Botany: Diversity and Ecology
  23. Marine Ecological Processes
  24. Marine Ecosystems
  25. Marine Fish
  26. Marine Invertebrate Zoology
  27. Marine Mammalogy
  28. Marine Mammals of the Salish Sea
  29. Marine Pollution
  30. Marine Zoology
  31. Nearshore Ecology Research Experience
  32. Oceans in Jeopardy
  33. Parasite Ecology
  34. Salmonid Behavior and Life History
  35. Special Topics in Biological Oceanography
  36. The Changing Arctic Ocean
  37. The Open Sea
  38. Tropical Marine Biology
  39. Vertebrates

Unfortunately, I cannot tell you the requirement to study Marine Biology because every institution has its own admission requirement for Marine Biology. If there are Marine Biology courses not mentioned please use the comment to let me know about them.

Timing is everything

Outwardly, then, some of the signs are troubling. Of those 172 species, close to a third are classified as species of concern in the U.S. and Canada. Managers would like to reverse that trend, but knowing where to start can be tricky. The Salish Sea’s bird species vary dramatically depending on the season, something that makes studying them a challenge. Ironically, that very challenge might also hold a clue to their declines.

In the Salish Sea, when it comes to birds, timing is everything.

In the summer, for example, the region is dominated by species such as common murres, Cassin’s and rhinoceros auklets, many of which breed in colonies along the outer coast. Most surveys of these summer birds show little in the way of consistent trends. Some, like the Cassin’s auklet, are increasing in number some, like the common murre, are fairly stable and some, like the endangered marbled murrelet, continue to decline.

Winter patterns are more consistent and clear. A number of birds that rely on the Salish Sea in winter show a plain trend: down. Scoters are declining. Loons are declining. And, of course, western grebes are almost entirely gone from the region. Why is that?

There is currently something going wrong along the American Pacific coast. Almost every day, an catastrophic animal die-off is being reported… But nobody knows why.

Here is an abbreviated list of creatures who have experienced mass die-off events since 2011-

1) Sea Stars 2) Bluefin tuna 3) Sardine, Anchovy, Herring 4) Sea Lions 5) marine birds 6) red King Crab 7) Pelicans 8) Pacific Oysters 9) Sockeye Salmon 1 0) Herring 11) plankton 12) Anchovies (again) 13) Whales 14) Tuna and Albacore 15) Most recently Tuna Crabs.

Natural causes in the environment are partly to blame so too are the corporations of man the effects of Fukushima, unleashing untold levels of radiation into the ocean and onto Pacific shores the cumulative effect of modern chemicals and agricultural waste tainting the water and disrupting reproduction.

A startling new report says in no uncertain terms that the Pacific Ocean off the California coast is turning into a desert. Once full of life, it is now becoming barren, and marine mammals, seabirds and fish are starving as a result. According to Ocean Health:

The waters of the Pacific off the coast of California are a clear, shimmering blue today, so transparent it’s possible to see the sandy bottom below […] clear water is a sign that the ocean is turning into a desert, and the chain reaction that causes that bitter clarity is perhaps most obvious on the beaches of the Golden State, where thousands of emaciated sea lion pups are stranded.

Over the last three years, the National Oceanic and Atmospheric Administration (NOAA) has noticed a growing number of strandings on the beaches of California and up into the Pacific north-west. In 2013, 1,171 sea lions were stranded, and 2,700 have already stranded in 2015 – a sign that something is seriously wrong, as pups don’t normally wind up on their own until later in the spring and early summer.

“[An unusually large number of sea lions stranding in 2013 was a red flag] there was a food availability problem even before the ocean got warm.”Johnson: This has never happened before… It’s incredible. It’s so unusual, and there’s no really good explanation for it. There’s also a good chance that the problem will continue, said a NOAA research scientist in climatology, Nate Mantua.

Experts blame a lack of food due to unusually warm ocean waters. NOAA declared an El Nino, the weather pattern that warms the Pacific, a few weeks ago. The water is three and a half to six degrees warmer than the average, according to Mantua, because of a lack of north wind on the West Coast. Ordinarily, the north wind drives the current, creating upwelling that brings forth the nutrients that feed the sardines, anchovies and other fish that adult sea lions feed on.

The warm water is likely pushing prime sea lion foods — market squid, sardines and anchovies — further north, forcing the mothers to abandon their pups for up to eight days at a time in search of sustenance.

The pups, scientists believe, are weaning themselves early out of desperation and setting out on their own despite being underweight and ill-prepared to hunt.


“These animals are coming in really desperate. They’re at the end of life. They’re in a crisis … and not all animals are going to make it,” said Keith A. Matassa, executive director at the Pacific Marine Mammal Center, which is currently rehabilitating 115 sea lion pups.

In the storm debris littering a Washington State shoreline, Bonnie Wood saw something grisly: the mangled bodies of dozens of scraggly young seabirds. Walking half a mile along the beach at Twin Harbors State Park on Wednesday, Wood spotted more than 130 carcasses of juvenile Cassin’s auklets—the blue-footed, palm-size victims of what is becoming one of the largest mass die-offs of seabirds ever recorded. “It was so distressing,” recalled Wood, a volunteer who patrols Pacific Northwest beaches looking for dead or stranded birds. “They were just everywhere. Every ten yards we’d find another ten bodies of these sweet little things.”

“This is just massive, massive, unprecedented,” said Julia Parrish, a University of Washington seabird ecologist who oversees the Coastal Observation and Seabird Survey Team (COASST), a program that has tracked West Coast seabird deaths for almost 20 years. “We may be talking about 50,000 to 100,000 deaths. So far.” (source)

100,000 doesn’t necessarily sound large, statistically speaking, but precedent in the history of recorded animal deaths suggests that it is, in fact massive. Even National Geographic is noting that these die off events are “unprecedented.” Warmer water is indicated for
much of the starvation faced by many of the dead animals.

Last year, scientists sounded the alarm over the death of millions of star fish, blamed on warmer waters and ‘ mystery virus’ :

Starfish are dying by the millions up and down the West Coast, leading scientists to warn of the possibility of localized extinction of some species. As the disease spreads, researchers may be zeroing in on a link between warming waters and the rising starfish body count. (source)[…]

Click picture for more info

The epidemic, which threatens to reshape the coastal food web and change the makeup of tide pools for years to come, appears to be driven by a previously unidentified virus, a team of more than a dozen researchers from Cornell University, UC Santa Cruz, the Monterey Bay Aquarium and other institutions reported Monday. (source)

Changing temperatures in the Pacific Ocean, driven by the natural cycle of gyres over decades, shifts wildlife populations, decimating the populations of species throughout the food chain, proving how fragile the balance of life in the ocean really is.

Recently, the collapse of the sardine population has created a crisis for fisheries and marine wildlife alike on the West Coast:

Commercial fishing for sardines off of Canada’s West Coast is worth an estimated $32 million – but now they are suddenly gone. Back in October, fisherman reported that they came back empty-handed without a single fish after 12 hours of trolling and some $1000 spent on fuel.

Sandy Mazza, for the Daily Breeze, reported a similar phenomenon in central California: “[T]he fickle sardines have been so abundant for so many years – sometimes holding court as the most plentiful fish in coastal waters – that it was a shock when he couldn’t find one of the shiny silver-blue coastal fish all summer, even though this isn’t the first time they’ve vanished.” [emphasis added]

“Is it El Nino? Pacific Decadal Oscillation? [La] Nina? Long-term climate change? More marine mammals eating sardines? Did they all go to Mexico or farther offshore? We don’t know. We’re pretty sure the overall population has declined. We manage them pretty conservatively because we don’t want to end up with another Cannery Row so, as the population declines, we curb fishing.” said National Oceanic and Atmospheric Administration (NOAA) official Kerry Griffin. (source)

According to a report in the Daily Mail, the worst events have wiped out 90% of animal populations, falling short of extinction, but creating a rupture in food chains and ecosystems.

And environmental factors are known to be a factor, with pollution from chemicals dumped by factories clearly tied to at least 20% of the mass die off events of wildlife populations that have been investigated, and many die offs implicated by a number of overlapping factors. TheDaily Mail reported:

Mass die-offs of certain animals has increased in frequency every year for seven decades, according to a new study.

Researchers found that such events, which can kill more than 90 per cent of a population, are increasing among birds, fish and marine invertebrates.

The reasons for the die-offs are diverse, with effects tied to humans such as environmental contamination accounting for about a fifth of them.

Farm runoff from Big Agra introduces high levels of fertilizers and pesticides which createoxygen-starved dead zones which fish and aquatic live is killed off. Also preset in agriculture waste are gender bending chemicals like those found in Atrazine, used in staple crop production, and antibiotics and hormones, used in livestock production, which creates hazardous runoff for fish populations:

Livestock excrete natural hormones – estrogens and testosterones – as well as synthetic ones used to bolster their growth. Depending on concentrations and fish sensitivity, these hormones and hormone mimics might impair wild fish reproduction or skew their sex ratios. (source)

Pharmaceutical contaminants are also to blame for changing the sex of fish and disrupting population numbers, while a study found that the chemicals in Prozac changed the behavior of marine life, and made shrimp many times more likely to “commit suicide” and swim towards the light where they became easy prey.

Fish farms also introduce a large volume of antibiotic and chemical pollution into oceans and waterways:

The close quarters where farmed fish are raised (combined with their unnatural diets) means disease occurs often and can spread quickly. On fish farms, which are basically “CAFOs of the sea,” antibiotics are dispersed into the water, and sometimes injected directly into the fish.

Unfortunately, farmed fish are often raised in pens in the ocean, which means not only that pathogens can spread like wildfire and contaminate any wild fish swimming past – but the antibiotics can also spread to wild fish (via aquaculture and wastewater runoff) – and that’s exactly what recent research revealed. (source)

Mass die offs of fish on the Brazilian coastline have linked to pollution from the dumping of raw sewage and garbage.

last year it was reported that a massive die off of bottlenose dolphins in the Gulf of Mexico was connected by researchers to BP’s Deep Water Horizon oil spill. Evidence was found in a third of the cases of lesions in the adrenal gland, an otherwise rare condition linked with petroleum exposure. More than a fifth of the dolphins also suffered bacterial pneumonia, causing deadly lung infection that is likewise rarely seen in dolphin populations.

This week we saw the latest victim of this, “the largest oceanic extinction level event since the last ice age”, when millions of tuna crab mysteriously washed up along beaches of Ensenada, Mexico.

After California, this latest mass die-off was reported in Ensenada, Baja California on May 14, 2016, where beaches turned completely red!

See the complete list of all the reported mass animal deaths for 2015 and 2016 by clicking the year.

Why are there no marine birds? - Biology

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[Book Review] Biology of marine birds



A text devoted to the biology and ecology of marine birds has not been published in the last 15 years. Although a number of more taxa-specific texts have been produced during that period, there has not been a single publication that attempted to review our knowledge of all the major seabird orders since the works of Nelson (1979), Croxall (1987), and Furness and Monaghan (1987). Following the publication of those works, a large and impressive body of literature has been produced. Given the rapid expansion of the field in the last two decades, the time was ripe for production of an extensive compendium on the biology, ecology, and conservation of the world's seabirds.

E. A. Schreiber and J. Burger are editors of this CRC publication, Biology of Marine Birds. The book consists of 19 chapters that vary in length from 15 to 51 pages. There are also two extensive appendices: (1) a list of seabird species (restricted to the orders Sphenisciformes, Procellariiformes, Pelecaniformes, and Charadriiformes, the latter limited to Stercorariidae, Laridae, Rhynchopidae, and Alcidae) and their IUCN status, and (2) a very useful table of species-specific life-history traits. The 19 chapters were prepared by 26 authors, among them some of the most respected and published seabird scientists in the world. A brief preface introduces the book, its objective (to provide an examination and summary of the research on seabirds), its audience (researchers, conservationists, managers, and policy-makers), and the taxa covered. The editors coauthored the introductory chapter, Seabirds in the Marine Environment. The authors describe distinctive characteristics of seabird life-histories in comparison to other taxa, hypotheses for why those lifestyles evolved and the potential role of energy limitation in the evolution of seabird life-histories. Along with a discussion of other common seabird traits, such as a propensity for colonial breeding, the authors also suggest directions for future research in seabird ecology.

Biology of Marine Birds

Patrick G. R. Jodice, Daniel D. Roby, Michelle Antolos, Donald E. Lyons, Daniel J. Rizzolo, Sadie K. Wright, Cynthia D. Anderson, Scott K. Anderson, S. Kim Nelson, Adrian E. Gall, Liv Wennerberg, Biology of Marine Birds, The Auk, Volume 120, Issue 1, 1 January 2003, Pages 240–245,

Biology of Marine Birds - E. A. Schreiber and J. Burger, Eds. 2002. CRC Press, Boca Raton, Florida. xxii + 722 pp. ISBN 0-8493-9882-7. $79.95.—A text devoted to the biology and ecology of marine birds has not been published in the last 15 years. Although a number of more taxa-specific texts have been produced during that period, there has not been a single publication that attempted to review our knowledge of all the major seabird orders since the works of Nelson (1979), Croxall (1987), and Furness and Monaghan (1987). Following the publication of those works, a large and impressive body of literature has been produced. Given the rapid expansion of the field in the last two decades, the time was ripe for production of an extensive compendium on the biology, ecology, and conservation of the world's seabirds.

E. A. Schreiber and J. Burger are editors of this CRC publication, Biology of Marine Birds. The book consists of 19 chapters that vary in length from 15 to 51 pages. There are also two extensive appendices: (1) a list of seabird species (restricted to the orders Sphenisciformes, Procellariiformes, Pelecaniformes, and Charadriiformes, the latter limited to Stercorariidae, Laridae, Rhynchopidae, and Alcidae) and their IUCN status, and (2) a very useful table of species-specific life-history traits. The 19 chapters were prepared by 26 authors, among them some of the most respected and published seabird scientists in the world. A brief preface introduces the book, its objective (to provide an examination and summary of the research on seabirds), its audience (researchers, conservationists, managers, and policy-makers), and the taxa covered. The editors coauthored the introductory chapter, Seabirds in the Marine Environment. The authors describe distinctive characteristics of seabird life-histories in comparison to other taxa, hypotheses for why those lifestyles evolved and the potential role of energy limitation in the evolution of seabird life-histories. Along with a discussion of other common seabird traits, such as a propensity for colonial breeding, the authors also suggest directions for future research in seabird ecology.

Chapters 2–19 cover a wide array of topics and, for the purpose of this review, have been organized into the following subject groupings: systematics and taxonomy (chapters 2 and 3), breeding and foraging ecology (chapters 4–10), physiology and energetics (chapters 11–14), environment and conservation (chapters 15–17), and ecology of shorebirds and wading birds in the marine environment (chapters 18–19). For each chapter we provide an abbreviated title and author list.

Chapters 2 (“Fossil Record”, by K. Warheit) and 3 (“Systematics and Distribution”, by M. de L. Brooke) provide the taxonomic foundation for this book by reviewing the fossil record and current systematics of seabirds. Chapter 2 reviews the seabird fossil record and also demonstrates the relevance of those data to contemporary studies of seabird ecology, evolution, and community structure. For example, Warheit describes how the current composition of seabird communities off South Africa and in the north Pacific reflect continental drift and sea-level changes, and how those events are chronicled in the seabird fossil record. Although this chapter does not include a discussion of when and where certain key seabird traits evolved (e.g. flightlessness or wing-propelled diving), it provides the reader with a strong foundation in seabird paleontology. Warheit also includes a meticulously researched appendix to this chapter where 369 fossil taxa are listed with temporal, spatial, and bibliographic information. Warheit's discussion of the seabird fossil record prepares the reader for the following chapter, by M. de L. Brooke, which reviews current seabird systematics. Brooke describes the four orders considered by most to constitute the seabirds and discusses some of the taxonomic relationships that are being reconsidered due to advances in molecular genetic techniques. The author succinctly contrasts the anatomical and molecular-based classification schemes without becoming tangled in taxonomic details that lie outside the scope of the chapter. This chapter also includes a useful discussion of the defining features and distribution of each seabird family, although in some cases photographs are relied upon to portray anatomical features that illustrations might have communicated more effectively.

Chapters 4–10 review topics related to seabird breeding biology, demography, and foraging ecology, with most of this section devoted to the former subject. These chapters represent the bulk of research on seabirds over the past three decades, and their content includes discussions of some of the attributes that make seabirds so interesting (e.g. colonial breeding, long-range foraging, low annual productivity). Many of the issues covered in these chapters can be traced back to some of the original, classic hypotheses developed during the earliest stages of research into seabird ecology (e.g. Ashmole 1963, Lack 1967).

Chapter 4 (“Colonial Breeding”, by J.C. Coulson) provides a lengthy review of colony structure and function in seabirds. Given that

95% of seabirds are colonial (a short-list of those species considered noncolonial should have been included), this topic deserves considerable attention. Approximately one-third of the chapter is dedicated to a discussion of theories and functions of colonial breeding, including classic theories of colony function (e.g. predator defense, Wynne-Edwards' [1986] concept of population self-regulation, and the information-center hypothesis) and four recent hypotheses of colony function proposed by Richner and Heeb ( 1996 group foraging) and Danchin and Wagner ( 1997 quality separation, sexual selection, and commodity selection). A substantial portion of the chapter is devoted to Coulson's discussion of 16 characteristics of colonial seabirds and seabird colonies. Many interesting speculations surface in this section, which is enhanced by examples from other taxonomic classes and avian orders.

Chapter 5 (“Demography”, by H. Weimerskirch) reviews the unique demographic aspects of seabirds and discusses relationships among demographic parameters at the order, family, and species level. Weimerskirch uses principal component analyses to examine seabird life-history data. Those analyses illustrate how seabird orders and families group together in relation to life-history attributes such as fecundity and life expectancy, and highlight potential directions for further investigation. This chapter illustrates the importance of demographic studies to seabird ecology. The discussion on the relation-ship between seabird demography and the marine environment, however, would have benefited from the use of examples where seabird demographic responses have been measured alongside independent measures of prey availability.

The following chapter (“Foraging Behavior and Food”, by D. A. Shealer) is well placed in the text to continue the discussion initiated in Chapter 5, given that the demographics of seabird populations are driven to a large extent by the ephemeral nature of the food supply and associated foraging strategies. Shealer reviews the current state of knowledge of seabird foraging behavior and food resources and discusses some of the morphological adaptations of seabirds that enhance their ability to forage in the marine environment. The author dedicates the majority of the chapter to a review of seabird foraging behaviors (e.g. daily patterns of foraging, olfaction, commensal foraging) and to a synthesis of the major prey items constituting seabird diets. Although already quite broad in its coverage, this chapter would have benefited from at least a brief overview of predictions from optimal foraging theory and its relationship to seabird foraging ecology. Also, there was little discussion of foraging via pursuit-diving in seabirds, although that topic might arguably be deserving of its own chapter given the wealth of research on the subject.

Chapter 7 (“Climate and Weather Effects”, by E. A. Schreiber) examines how seabird populations are affected by climate and weather events that occur across a range of temporal scales from days to years. Both direct and indirect effects of climactic events on seabirds are considered, including issues related to thermoregulation, flight dynamics, and prey availability. Schreiber examines how those factors ultimately affect seabird population dynamics, often via changes in rates of annual productivity. Schreiber describes what has been learned about seabird ecology in relation to El Niño southern oscillation (ENSO) events. The author drew on years of experience studying those relationships in the tropical Pacific to impart a keen insight into how such events may have shaped some of the early theories of and investigations into seabird breeding biology, especially in the tropics. In fact, this section provides an excellent review of the ENSO phenomena for any reader, whether concerned about seabird ecology specifically or ENSO events in general. Other longer-term climactic events, such as the Pacific decadal oscillation and global warming, were not discussed despite their potential and, in some cases, known effects on seabird populations.

Chapter 8 (“Breeding Biology and Life Histories”, by K. C. Hamer, E. A. Schreiber, and J. Burger) begins by reviewing life-history traits of seabirds and by clarifying the often-confused terms “life-history traits” (characteristics that are influenced at the evolutionary scale) and “life-table variables” (indices of individual performance). A discussion of the influences of age, weather, and food availability on the timing of breeding follows, although the discussion of effects of food availability merits more attention than is given. The core of this chapter consists of an excellent and thorough discussion of seabird breeding biology and life histories. This section, which is one of the strongest in the entire book, includes discussions of the evolution of nestling obesity, the relationship between latitude and chick-rearing period, the importance of stomach oil production in the Procellariiformes, and the variation in chick attendance among species. This section includes many thoughtful hypotheses that are backed up by clearly illustrated tables and figures.

Chapter 9 (“Site and Mate Choice”, by J. Bried and P. Jouventin) provides a well-referenced discussion of site and mate choice that concentrates on the relationship between seabird reproductive constraints and the degree of mate fidelity from an evolutionary point of view. The chapter begins by reviewing classic site- and mate-choice theories and progresses to a discussion of the constraints on site and mate selection of low clutch size, extended parental care, high juvenile mortality, and breeding latitude. Unfortunately, the discussion of habitat selection in reference to breeding site choice was relatively brief and merely touched upon the relationship between nest-site location and its proximity to key food resources. One of the strengths of this chapter was the discussion of mate-selection theory, which reviewed some of the costs of mate selectivity and included a review of current theories examining mate choice on the basis of physical characteristics (e.g. body condition), time of arrival, and territory quality. This chapter also included an extensive table that compiled information on nest-site fidelity, mate fidelity, survival, average life expectancy, and body mass for 93 seabird species.

Colonial nesting marine birds have always provided an outstanding opportunity for biologists to examine the roles and complexity of visual and auditory displays during courtship, mating, and chick-rearing. J. B. Nelson and P. H. Baird present the reader with a wealth of examples on those topics in chapter 10 (“Communication and Displays”). The chapter is organized into four primary sections based on the four major seabird orders. Each section covers basic breeding biology, territorial behavior, pair relationships, incubation and chick-rearing, and behavior outside the breeding season. The authors also discuss a wide-range of visual displays and provide written and illustrative descriptions of those, although little attention is given to vocal or olfactory communication. Although the illustrations greatly aid the reader in understanding those displays, the publishers could have supplemented the text via the web or a CD with a collection of images, sounds, or even short video clips exemplifying seabird communication and display.

The following three chapters (chapters 11–14) provide a review of the major physiological and energetic features of seabird ecology. Over the past three decades, research on the physiology and energetics of seabirds has grown considerably and has provided a great deal of insight, not only into seabird ecology, but also into the broader fields of avian physiological ecology and environmental physiology. The study of seabird energetics provides an opportunity to under-stand the mechanisms and constraints underlying seabird life history and demography and, although not stated explicitly in the text, the material presented in those four chapters clearly makes that point.

Chapter 11 (“Energetics”, by H. I. Ellis and G. W. Gabrielsen) thoroughly reviews the biology of adult seabird basal and field metabolic rates (BMR and FMR, respectively) as well as ecological correlates of both. This well-referenced chapter includes extensive data tables that compare BMR measures in 77 seabird species and FMR measures in 37 species. Each of the comparisons leads to a new allometric equation relating metabolic rate to body mass. The authors also provide useful reviews and critiques of measurement techniques for both BMR and FMR. Ellis and Gabrielsen also discuss central issues related to sea-bird thermoregulation, which they summarize in an extensive table reviewing thermal conductance in 35 seabird species. The authors use those data to produce a new allometric equation relating conductance to body mass. The new allometric equations presented by the authors advance our understanding of seabird energetics in important ways and enhance our ability to predict energetics and conductance. The chapter would have benefited, however, from the addition of figures that illustrated those allometric relationships and from more discussion of the ecological (as opposed to physiological) relevance of those attributes.

Whereas chapter 11 focuses on adult seabirds, the emphasis of chapter 12 (“Reproductive Physiology”, by G. C. Whittow) is its coverage of incubation and embryonic physiology. The author discusses the reproductive physiology of breeding adults, describes the process of egg formation, and briefly touches upon adult hormone changes associated with incubation. A review of egg formation and the energetics of incubation follow, although differences in incubation strategies among taxa are not discussed. The author also provides an overview of embryonic development, which provides a good transition to the following chapter (“Chick Growth and Development”, by G. H. Visser). In chapter 13, Visser focuses on growth patterns and energetics of young seabirds and methods for measuring energy budgets. This clear and well-written chapter begins with a discussion of interorder, interspecific, and intraspecific variation in growth-rate parameters, with emphasis on deviations from the seabird norm. That approach allowed for clear comparisons among taxa and for easy identification of species that were most different from the norm. A major emphasis of the chapter is the energetics of chick growth. Important components of chick energy budgets are summarized, including a brief review of available data on assimilation efficiencies in seabird chicks, and a detailed overview of methods used to measure energy budgets in developing chicks. Visser also presents detailed methodology for four techniques used to measure energy budgets: periodic chick weighing, time–energy budgets, water influx rates, and the doubly labeled water method. The author draws particular attention to fractionation effects on the accuracy of the doubly labeled water method and rightfully argues for a set of standardized assumptions to be used when calculating energy expenditure rates using that method. The chapter concludes with a novel comparative analysis of energy budgets for seabird family units.

Chapter 14 (“Water and Salt Balance”, by D. L. Goldstein) is, with the exception of chapter 1, the shortest of the book. It begins with a discussion of the avenues of input and output for water and salt in marine birds, including a summary of recent work on renal form and function in marine birds, much of which the author has been involved with. The section on salt (nasal) glands is brief, seemingly too brief for a group of birds that have taken that adaptation to its pinnacle. The section on inter- and intraspecific variation in seabird osmoregulation is thin, mostly because recent research in that area has been limited, but some studies were missed. This chapter would have benefited from illustrations of some of the anatomical features discussed in the text. The role of osmoregulation as a constraint on seabird reproductive behavior and ecology presents opportunities for new and interesting avenues of investigation.

Chapters 15–17 focus on management and conservation issues pertaining to seabirds. The editors included chapters covering effects of extrinsic chemicals and pollutants on seabirds (chapter 15), interactions between seabirds and fisheries (chapter 16), and sea-bird conservation issues (chapter 17). Although this list does not cover all of the pertinent conservation issues (e.g. predation and competition from invasive species could warrant a chapter all its own), it does provide the reader with a substantive review of some of the most important conservation and management issues facing seabird biologists.

Chapter 15 (“Chemicals and Pollution”, by J. Burger and M. Gochfeld) draws on the authors' many years of research experience on effects of marine pollutants on birds to develop a discussion of the various major pollutants (metals, organochlorine compounds, petroleum products, and plastics). Burger and Gochfeld provide a thorough discussion of the utility and limitations of using seabirds as bioindicators of pollutants. Differences in vulnerability of seabirds as related to trophic feeding level, age, gender, and taxa are reviewed, although that discussion is limited to differences in documented contaminant levels within each of those aforementioned groups, rather than mechanisms underlying those differences. The authors include contaminant-specific reviews for cadmium, lead, mercury, and selenium, and also provide case studies of their research into effects of lead exposure on seabirds. Treatment of organo-chlorine compounds focuses on pesticides and PCBs. Petroleum products and oil spills are only briefly covered relative to the magnitude of their effect on seabird populations. Biomarkers of pollution, particularly induction of mixed-function oxidases and their uses and limitations, are not discussed. The chapter does well, however, at emphasizing the relationship between sublethal toxicity at the individual level and effects on reproduction and population dynamics.

Another important anthropogenic factor affecting seabird populations is the interaction between seabirds and fisheries. W. A. Montevecchi reviews that topic in chapter 16 (“Fisheries Interactions”). The introduction describes both current and historic inter-actions between seabirds and fisheries. Montevecchi then discusses both positive and negative influences of fisheries on marine birds, as well as effects of seabirds on fisheries. Emphasis is placed on differentiating potential effects of fisheries on adult survival from those on reproduction. This chapter provides excellent examples of direct effects of fisheries on seabirds (e.g. gear entrapment), as well as examples of indirect effects of fisheries on seabirds (e.g. ecological repercussions of prey depletion). Although the author discusses sources of adult mortality related to fisheries and provides suggestions for management and mitigation, there is no discussion of the methods used to assess mortality estimates or other fishery–seabird interactions. The author's review of the positive effects of fisheries on seabirds highlights the ecological interactions between fishery activities and the marine food web, and demonstrates the difficulty in categorizing an interaction as positive or negative for all seabirds. The author offers valuable suggestions for management, such as using consumer pressure and economic incentives as means to promote ecologically responsible fishing practices.

Chapter 17 (“Conservation”, by P. D. Boersma, J. A. Clark, and N. Hillgarth) briefly reviews conservation issues for seabirds, with special attention to effects of habitat modification, introduced species, human harvest, and human disturbance. Other threats to seabirds, such as pollution and fisheries interactions, are covered in their own chapters, but mentioned here as well. The chapter provides an overview of the degree of legal protection afforded to marine birds as well as a discussion of progress that has been made in the arena of seabird conservation. Although this chapter presents a succinct review of conservation issues, including case studies that highlight both successes and ongoing challenges in seabird conservation would have enhanced it. A notable omission from this chapter was the lack of discussion pertaining to global warming and its current and potential effect on seabird populations, especially at high latitudes. The authors refer the reader to chapter 7 for a discussion of climate change, but nowhere in the book are the conservation implications of global warming fully discussed.

Chapters 18 (“Shorebirds in the Marine Environment”, by N. Warnock, C. Elphick, and M. A. Rubega) and 19 (“Wading Birds in the Marine Environment”, by P. C. Frederick) broadened the scope of this text by including reviews of taxa that are not typically considered marine birds but that may spend substantial portions of the annual cycle in marine environments. The shorebird chapter provided a brief review of shorebird biology before focusing on shorebird use of coastal habitats and influences of tides and climate on ecology, with particular emphasis on foraging behavior. This chapter also included brief sections on phalarope ecology, shorebird migration in the marine environment, and conservation issues. Similarly, chapter 19 reviewed wading-bird biology as it relates to the marine environment. Frederick provided the reader with an extensive overview of the current state of knowledge of marine waders, emphasizing wading-bird reproductive and behavioral ecology. This chapter thoroughly reviewed the broad range of foraging strategies employed by waders in marine environments, as well as foraging constraints and prey. As in the previous chapter, the author also provided an overview of conservation issues related to waders in the marine environment.

Biology of Marine Birds fills a vacant niche for those seeking a current review of seabird biology and ecology. The 19 chapters cover a wide array of topics, although a noticeable inconsistency within the book is the breadth and depth of each chapter. For example, some chapters are quite lengthy and provide in-depth reviews of the material as well as new analyses, whereas others provide only a brief overview of the focal topic. Most chapters do, however, provide the reader with a substantive review of prior research and suggestions for future research. Furthermore, although the book covered a wide array of topics, we felt that certain areas deserved greater attention. Those include, but are not limited to predation, disease, and parasites at colonies behavior and physiology of pursuit-diving nutritional ecology genetics and population structure ecology during the nonbreeding season, including migration behavior decadal-scale shifts in marine trophic structure and global warming. The inclusion of the shorebird and wading-bird chapters increased the scope of the text, but the omission of sections on other marine-dependent species such as sea ducks, loons, and grebes was notable.

1 Marine Fish

The study of fish, ichthyology, includes both freshwater and marine species. Since at least 25,000 species of fish exist in all their diverse categories -- including cartilaginous species likes sharks and rays, as well as the bony fishes -- this is a broad field for study. The marine biologist would technically study only saltwater fishes, though his special area of study may involve a more specific interest in one or more species and concentrate on a particular aspect within that study -- such as reproduction, migratory behaviors or even fish farming.

Why biodiversity among marine mammals and birds generally rises in cold, temperate waters

An African penguin (Spheniscus demersus) on a beach in South Africa. A new study examines why biodiversity among warm-blooded marine predators such as whales, seals and penguins rises in cold, temperate waters. Credit: Adam Wilson

In ecology, the diversity of species generally increases as you move toward the warmer latitudes of the tropics.

A new study explores a curious exception to this trend, examining why biodiversity rises in cold, temperate waters among warm-blooded marine predators such as whales, seals and penguins.

The research—published on Jan. 25 in the journal Science—presents a possible explanation for this unusual pattern.

"We show with data and theory that cold waters slow fishes' and sharks' metabolism, causing sluggish movement and giving mammals and birds important hunting and competitive advantages," says John Grady, a postdoctoral research associate at the National Great Rivers Research and Education Center and former postdoctoral researcher at Michigan State University, who led the study. "Sharks are easier to avoid and fish are easier to catch when the water is cold."

"As we conclude in the paper, 'Overall, warm-bodied predators are favored where prey are slow, stupid and cold,'" says co-author Adam Wilson, Ph.D., a biogeographer at the University at Buffalo. Wilson is an assistant professor in the Department of Geography in the UB College of Arts and Sciences.

A humpback whale (Megaptera novaeangliae) pictured in Cape Cod Bay off the coast of Massachusetts in the United States. Credit: Adam Wilson

"We are living through an era of rapid environmental change and biodiversity loss," Wilson adds. "Understanding the mechanisms that led to the current spatial distribution of biodiversity is critical to conserving it for future generations."

The study was an international collaboration, with contributors from Michigan State University, Bryn Mawr College, the University of Arizona, the University of New Mexico, the University of Freiburg in Germany, Dalhousie University in Canada, the U.N. Environment Programme World Conservation Monitoring Centre in the United Kingdom, UB, the National Great Rivers Research and Education Center, and Washington University in St. Louis.

Using data to quantify and explain marine predator diversity

As part of the study, Wilson co-developed a workflow that the team used to quantify and summarize the geographic distribution of almost 1,000 species of sharks, fish, reptiles, mammals and birds.

"We used these data to show how warm-blooded marine predators such as seals, whales and penguins do not follow the typical geographic pattern of increasing biodiversity near the tropics. Our analysis showed that the diversity of these predators systematically increases toward the poles relative to cold-blooded competitors such as large sharks and fish," Wilson says. "This curious fact led to the development of the theory presented in the paper, which explains the patterns of biodiversity by taking into account the relative speed at which predators pursue their prey in different water temperatures."

Magellanic penguins (Spheniscus magellanicus) near Navarino Island, Chile. Credit: Adam Wilson

Scientists found evidence to support this hypothesis when they examined consumption patterns among warm-blooded seals and active-hunting cetaceans (including dolphins, porpoises, beluga and narwhal).

"Analyzing global patterns of marine mammal abundance and consumption, we find seals and dolphins collectively consume approximately 80 times more of the available food near the polar seas than the warm equator," Grady says.

This may help to explain why these warm-blooded predators are more abundant and diverse in cold seas, Grady adds.

No-take zone

A no-take zone is an area set aside by a government where no extractive activity is allowed. Extractive activity is any action that extracts, or removes, any resource.

Biology, Ecology, Earth Science, Oceanography, Geography

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A no-take zone is an area set aside by the government where no extractive activity is allowed. Extractive activity is any action that removes, or extracts, any resource. Extractive activities include fishing, hunting, logging, mining, and drilling. Shell collecting and archaeological digging are also extractive.

No-take zones usually make up part of larger protected areas. These protected areas, sometimes part of national or state parks, are located on both land and open water, such as lakes and oceans. No-take zones offer a greater amount of protection to the ecosystems, habitats, and species within the boundaries of those larger, and less restrictive, protected areas.

No-take zones are a specific type of marine protected area (MPA). According to the National Oceanic and Atmospheric Administration (NOAA), no-take MPAs totally prohibit the extraction or significant destruction of natural or cultural resources.

No-take MPAs are rare. Most countries and states have fisheries that depend on the extraction of marine life. Sport fishing and commercial fishing are often important industries in coastal areas. Throughout the world, the fishing industry is the most powerful opponent of no-take zones. However, archaeologists, treasure hunters, and the oil and mining industries are also often critical of no-take MPAs.

Most no-take zones are often part of multiple-use MPAs, where different levels of activity are allowed in different zones. Multiple-use MPAs regulate the amount of extractive activity, as well as recreation and scientific research, that can take place in a protected area.

No-take zones within multiple-use MPAs usually protect the spawning grounds of many aquatic species. They may also serve as outdoor laboratories that allow scientists to compare the undisturbed areas of a no-take area to those impacted by human activities. Through these experiments, scientists are better able to understand how human activities affect the marine environment.

Channel Islands National Marine Sanctuary, California

The Channel Islands National Marine Sanctuary is a multiple-use MPA located in the Santa Barbara Channel, off the southern coast of the U.S. state of California. The sanctuary encompasses about 3,807 square kilometers (1,470 square miles) of water surrounding Anacapa, Santa Cruz, Santa Rosa, San Miguel, and Santa Barbara Islands. The islands surrounded by the no-take MPAs are not inhabited by people, and only limited scientific research is allowed on them.

In 2007, NOAA added nine new marine zones to the sanctuary, eight of which are no-take marine reserves. These new no-take areas prohibit all extractive activities and injury to sanctuary resources.

The Channel Islands no-take zones protect a great variety of organisms, including large forests of giant kelp, fish, invertebrate populations such as shrimp and clams, and diverse species of marine birds. Marine mammals, such as whales and sea lions, also inhabit the sanctuary. The no-take zones provide full or part-time habitats for endangered species, including blue, humpback, and sei whales, southern sea otters, California brown pelicans, and the California least terns.

Great Barrier Reef Marine Park, Australia

Located off the northeast coast of Australia, Great Barrier Reef Marine Park begins at the tip of Cape York in the territory of Queensland and extends south almost to the city of Bundaberg. The park is only slightly smaller than the nation of Japan, and stretches approximately parallel to the Queensland coast for more than 2,240 kilometers (1,400 miles).

In the Great Barrier Reef, no-takes areas are also known as Green Zones. Within Green Zones, recreational activities such as boating, snorkeling, and diving are allowed. However, fishing and coral collecting are entirely prohibited.

Until recently, no-take zones made up less than five percent of Great Barrier Reef Marine Park. Within the last ten years, the network of no-take areas now covers more than 33 percent of the MPA.

Green Zones improve the protection of the regions biodiversity through a series of strict guidelines. All Green Zones in the MPA are at least 10 kilometers (6 miles) wide.

The Green Zone network offers at least 20 percent protection per bioregion. A bioregion is a geographic region that is larger than a single ecosystem. Some of the bioregions protected by no-take zones in the Great Barrier Reef include coastal beaches, lagoons, and more than 30 types of coral reefs.

Great Barrier Reef Marine Park supports a phenomenal variety of organisms, including many vulnerable or endangered species. Four hundred coral species make up the majority of the reef. Six species of sea turtles come to the reef to breed, while 215 species of birds regularly visit the reef, with some nesting on nearby islands. The islands also support 2,195 known plant species. More than 1,500 species of fish live on the reef, and thirty species of whales, dolphins, and porpoises have been recorded within the MPA.

The Great Barrier Reef is one of the richest, most complex, and most diverse ecosystems in the world. It is also one of Australias most profitable tourist centers. Tourists visit the Great Barrier Reef to enjoy the largest coral reef in the world, its colorful and unique habitats, and the array of recreational activities in the area. They also come to participate in sport fishing and other extractive activities.

Australia has large fisheries near the Great Barrier Reef. Marlin, coral trout, bass, snapper, and a wide variety of sharks are harvested near the park. Some of these fish are also harvested in the park itself, in zones that allow for commercial or sport fishing.

The network of no-take zones allows leaders to manage the park to support both the environment and economy of the area.

Marine Ecosystems

Marine ecosystems are aquatic environments with high levels of dissolved salt. These include the open ocean, the deep-sea ocean, and coastal marine ecosystems, each of which have different physical and biological characteristics.

Biology, Ecology, Conservation, Earth Science, Oceanography

Coral Reef State Park

Coral reefs are a diverse form of marine ecosystem, which in total may account for a quarter of all ocean species. Several types of fish and coral are shown here at John Pennekamp Coral Reef State Park in Florida, United States.

Photograph by James L. Amos

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Marine ecosystems are aquatic environments with high levels of dissolved salt, such as those found in or near the ocean. Marine ecosystems are defined by their unique biotic (living) and abiotic (nonliving) factors. Biotic factors include plants, animals, and microbes important abiotic factors include the amount of sunlight in the ecosystem, the amount of oxygen and nutrients dissolved in the water, proximity to land, depth, and temperature.

Sunlight is one the most important abiotic factors for marine ecosystems. It&rsquos so important that scientists classify parts of marine ecosystems&mdashup to three&mdashby the amount of light they receive. The topmost part of a marine ecosystem is the euphotic zone, extending down as far as 200 meters (656 feet) below the surface. At this depth, there is sufficient light for regular photosynthetic activity. Most marine life inhabits this zone. Below the euphotic zone is the dysphotic zone, which can reach from 200 to as deep as 1,000 meters (656 to 3,280 feet) below the surface. At these depths, sunlight is still available, but only enough to facilitate some photosynthesis. Below the dysphotic zone lies the aphotic zone, which does not receive any sunlight.

Types of Marine Ecosystems

Scientists divide marine ecosystems into several broad categories, although there are discrepancies depending on the source about what qualifies as a marine ecosystem. The number of marine ecosystems is actively debated. Although there is some disagreement, several types of marine ecosystems are largely agreed on: estuaries, salt marshes, mangrove forests, coral reefs, the open ocean, and the deep-sea ocean.

An estuary is a coastal zone where oceans meets rivers. Here, nutrients and salts from the ocean mix with those from the river in regions sheltered from extreme weather. As a result, estuaries are among the most productive places on Earth and support many types of life. In addition, because they are located where rivers join the ocean, estuaries have traditionally supported many human communities and activities like fishing, shipping, and transportation.

While estuaries form where ocean meets rivers, salt marshes occur where oceans meets land. These places are rich in nutrients from sediment brought in by the ocean. Marshes are regularly flooded by high tides, making the surrounding ground wet and salty. As a result, the soil is low in oxygen and filled with decomposing matter. These ecosystems are dominated by low-growing shrubs and grasses.

Another coastal ecosystem is the mangrove forest. Mangrove forests are found in tropical areas. Thesee ecosystems frequently flood with ocean water, submerging the roots of mangrove trees. The root systems of mangroves filter out salt and sit above ground to access oxygen. These trees provide a home for a variety of species. Animals, such as fish, crabs, shrimp, reptiles, and amphibians, live among the mangrove&rsquos roots while its canopy provides a nesting site for birds.

A bit farther out into the tropical sea are coral reefs, euphotic-zone ecosystems built from the exoskeleton secreted by coral polyps. These exoskeletons form complex structures that shelter many different organisms. Coral reefs are extremely diverse ecosystems that host sponges, crustaceans, mollusks, fish, turtles, sharks, dolphins, and many more creatures. By some counts, coral reefs can account for a quarter of all ocean species.

Beyond the coral reefs lies the open ocean. Open ocean ecosystems vary widely as the depth of the ocean changes. At the surface of the ocean, the euphotic zone, the ecosystem receives plenty of light and oxygen, is fairly warm, and supports many photosynthetic organisms. Many of the organisms that we associate with marine ecosystems, such as whales, dolphins, octopi, and sharks, live in the open ocean.

As the depth of the ocean increases, it gets darker, colder, and with less available oxygen. Organisms living in deep-sea ecosystems within the dysphotic and aphotic zones have unusual adaptations that help them survive in these challenging environments. Some organisms have extremely large mouths that allow them to catch whatever nutrients fall from shallower ocean depths. Others have adapted to get their energy via chemosynthesis of chemicals from hydrothermal vents.

Coral reefs are a diverse form of marine ecosystem, which in total may account for a quarter of all ocean species. Several types of fish and coral are shown here at John Pennekamp Coral Reef State Park in Florida, United States.