PLEASE LIMIT RESPONSES TO SPACE PROVIDED. 100 points total. SHORT ANSWER SECTION. 10 POINTS PER QUESTION. RESPOND TO ALL QUESTIONS IN THIS SECTION.

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1 FISH 475: MARINE MAMMALOGY, SPRING MIDTERM EXAMINATION. (see end of file for exam result statistics) NAME: KEY UW STUDENT NUMBER: N/A PLEASE LIMIT RESPONSES TO SPACE PROVIDED. 100 points total. SHORT ANSWER SECTION. 10 POINTS PER QUESTION. RESPOND TO ALL QUESTIONS IN THIS SECTION. 1. Indicate the scientific name of the family to which each of the following species of marine mammal belongs (marked by Glenn VanBlaricom): Sperm whale: Physeteridae Pygmy sperm whale: Kogiidae Pygmy right whale: Neobalaenidae Dugong: Dugongidae California sea lion: Otariidae 2. When walruses leave the water and haul out on ice or land, their skin color is often initially gray or a pale reddish-brown. After resting on the haul-out for awhile (30 minutes or more), the skin color typically becomes a much deeper redbrown in color. Summarize the anatomical features and physiological processes that cause the color change pattern (marked by Glenn VanBlaricom). The color change results from an increase in peripheral blood circulation, acceptable because the hauled out walrus is no longer immersed in sea water and susceptible to high rates of heat loss. Increased peripheral circulation is necessary, when it can be done, in order to sustain the metabolic and physiological needs of peripheral tissues. The change in peripheral circulation occurs when a) vasodilation occurs, and b) when peripheral blood shunts, typically open to return blood to the body core in order to minimize peripheral heat loss when the animal is immersed in cold water, are closed, thus routing arterial blood to the peripheral tissues, including the skin.

2 NAME: KEY 3. Respond to one of the two questions (a or b) posed below the figures (space for response on following page) (marked by Teresa Mongillo): a) Referring to figure a: Transient killer whales (the marine-mammal eaters) have higher levels of PCBs than resident populations (the fish-eaters) in the Washington-British Columbia region, and the Southern residents have higher levels than the Northern residents. Briefly explain the differences. b) Referring to figure b: PBDEs, or the flame-retardants, are similar in molecular structure to PCBs and are considered an emerging threat. PBDE levels do not appear to show the same trend as PCBs (described in question a and figure a above). Briefly explain the lack of similarity in trends.

3 NAME: KEY 3 (continued). Space for response: Question a: PCBs bioaccumulate. Therefore, species at the top of the food chain generally have higher contaminant levels. Because transient killer whales consume prey at a higher trophic level, they will accumulate higher PCB levels than residents that eat lower on the food chain. A second factor that affects contaminant concentrations in individuals is the geographic region occupied by the animals. Areas that are near industry/point sources of pollution will in general have higher contaminant levels. Northern resident whales consume prey at the same trophic level as the SRKWs, but because the northern residents consume prey that has a distribution farther from point sources, they will have lower levels of PCB contamination. Question b: PBDEs are relatively new to the environment, so we are not seeing the same trends as we see in PCBs (factors such as age, sex, and birth order don't appear to be influencing these concentration levels). Because PBDEs are new to the environment, they are not evenly distributed among species, trophic levels, or regions, like we would expect for contaminants present in the marine environment for many decades. However, there is a range of theories as to why the few transients that were sampled had similar levels as southern residents. Full credit will be given for responses noting influential factors such as sex, age, birth order, diet, and geographic region as well as the PBDE trend (new to the environment and exponential increase). 4. What category of terrestrial mammal might give rise to the next evolutionary transition to marine life? Provide two reasons for your choice [Note: Category can mean any recognized type of terrestrial mammal. Examples might be rabbits, fruit bats, or anteaters. Bears, otters, and hippopotamus are excluded as options, given that they are obviously already transitional forms](marked by Teresa Mongillo). There is no correct response to this question. A complete response will include arguments about how the chosen group of terrestrial mammals is predisposed to evolutionary accommodation to marine life, in the context of at least two of the following: prey availability, prey capture, movement, thermoregulation, tolerance of high ambient pressure, and the ability to obtain water of sufficient purity to sustain mammalian metabolic processes.

4 NAME: KEY 5. Satellite telemetric devices attached to free-ranging marine mammals often transmit data to satellites operated by the Service Argos Company of France. How has bandwidth configuration in the Argos Satellite System influenced the type and quantity of data that can be obtained from marine mammals tagged with satellite telemetric devices (marked by Brianna Blaud)? The Argos System, with satellites in orbit for over two decades, is now antiquated with regard to contemporary data acquisition, transmission, and processing capabilities. The key limitation is the rate at which data can be received by receivers onboard the satellites. Transmitter-bearing marine mammals can only transfer data to satellite receivers when the animals are on the surface. Since surface durations typically range from a few seconds to a few minutes, there is typically insufficient time to upload complete data files given the antiquated Argos receivers. As a consequence, size of transmitted files must be reduced in size by the telemetric devices attached to the animals prior to uploading. A common example is binning of data in summary categories prior to transmission. The result is a limit on resolution and statistical power of the data once they are received by satellites, and a loss of detail in the data set. It is understood that this issue was not a major emphasis in the lecture of 22 April by Dr. Lander. As a consequence, substantial latitude was allowed in evaluations of responses. 6. Please respond to one of the following two questions relating to the lab portion of the course (marked by Brianna Blaud): 1) You have found a marine mammal skull, with both mandibles (lower jaws) still attached and all teeth present, on a beach on Puget Sound. The front part of the skull is extended into a rostrum of moderate length. There are teeth in both the upper and lower jaws. The teeth are numerous, and all have the same shape. To what major category (higher than family) of marine mammals does the species belong? Describe one reliable criterion you would use to determine the family to which the species belongs. Major category: Odontocete cetaceans Reliable criterion: We are in Puget Sound, so we can rule out belugas, narwhals, and all river dolphin species with biogeographic criteria. Given that the teeth are supernumerary, homodont, and present in both upper and lower jaws, we know that the skull must be from a porpoise or a dolphin. We can use shape of individual teeth (i.e., conical vs. spatulate [spoon-shaped]) to make the final decision regarding family.

5 NAME: KEY 2) Sea otters often leave a trail of small air bubbles during foraging dives. Where do the bubbles come from? What is their significance? Assume that sea otters keep their mouths and nostrils tightly closed during dives, and are not subject to flatulence. The air bubbles are forced out of the fur of sea otters by increased ambient pressure during dives. The significance of air in the fur is that it forms a blanket of air against the skin, held in place by the fur and associated oils secreted by glands in the skin, crucial to effective thermoregulation by sea otters. Following foraging episodes, sea otters spend substantial time and effort grooming the fur, in order to recharge the air layer diminished by bubble loss during dives, as well as to clean the fur and stimulate oil secretion by skin glands. ESSAY QUESTIONS. STUDENTS WERE ASKED TO CHOOSE ONE OF THE FOLLOWING QUESTIONS AND PROVIDE A RESPONSE. 40 POINTS. 1. When male killer whales go through puberty their dorsal fins grows substantially, increasing in both height and surface area. Conventional wisdom is that the enlarged fin is a secondary sexual characteristic of potential value in demonstrating presence and prowess, both to attract adult females receptive to mating, and to intimidate other males that might be competitors for mating opportunities. An alternative hypothesis is that the enlarged fin allows the individual males to thermoregulate testicular tissues, now active and temperaturesensitive as a result of sexual maturity, through a system of circulatory modifications and shunts that bring cooled blood from the dorsal fin to the testicles. Describe a plan for a study to determine which hypothesis is correct. Assume that you have all necessary research permits for invasive study, and have access to captive animals if you think they would be needed (marked by Glenn VanBlaricom). There is no right answer to this question, but rather a number of possible approaches that might succeed in providing answers. At a conceptual level, the indicated study would need to address the two hypotheses. It is important to recognize that both hypotheses must be tested in some way, and to recognize that the two hypotheses may not be mutually exclusive. Thus, evidence for disproof of one of the hypotheses does not automatically mean that the other hypothesis is supported. It is also important to recognize that even the most practical approaches to evaluation of this question will be challenging logistically, take a long time to implement, and likely will require substantial funding. Although the question specifies the assumption that all required permits are in hand, it is also important to appreciate how difficult

6 the permitting procedure likely would be for the work needed to address the question. The hypotheses: a) The enlarged dorsal fin is a secondary sexual characteristic of value in breeding success as determined by social factors; b) The enlarged dorsal fin functions as a heat radiator to limit temperature in the internal testicular area, in conjunction with specialized circulatory shunts. The most practical way to evaluate the first hypothesis is probably through collection of biopsy samples from a large number of individual whales in order to use genetic methods for determination of paternity, and therefore breeding success. The paternity data could be compared to data on dorsal fin size of males present in the subject population, to establish or refute a correlation of fin size and breeding success. There are of course other ways to measure paternity in the field, but in the case of killer whales field observations are not likely to be fruitful, since copulations are so difficult to see and it may not be possible to determine which copulations result in pregnancies. An additional problem with field determination of paternity is the long time line likely required (i.e., many years) to get large enough sample sizes for statistically robust analyses. The second hypothesis could be most readily tested by obtaining semen samples from males and evaluating viability of sperm, then examining the linkage of sperm viability with male dorsal fin size, by individual male, in the subject population. A second approach might involve using temperature probes, perhaps inserted via the anal opening into the colon, in order to directly measure temperature regulation in the testicular area as compared to other internal tissues proximate to the colon. The magnitude of temperature differences between the testicular area and other internal tissues could be evaluated as a function of dorsal fin size, by individual studied, in order to evaluate the hypothesis. Evaluation of the second hypothesis would be assisted by careful dissection of dead stranded whales, if they could be located while fresh and intact, to confirm that the appropriate system of circulatory shunts is present to provide testicular cooling in association with the dorsal fin. There are of course other possible methods for testing the hypotheses. Full credit is given for approaches that are reasonable in terms of cost, timeline, and logistical feasibility. 2. Imagine that global climate change facilitates significant intensification, over the next two centuries, of mean rates of solar energy (i.e., sunlight) input on the eastern edges of the major ocean basins on earth. How might such changes in the influx of solar energy influence the size and dynamics of pinniped populations

7 The most productive regions along the eastern margins of the major ocean basins are the eastern boundary currents, such as the California (NE Pacific), Humboldt (SE Pacific), and Benguela (SE Atlantic). These current systems are best developed in middle latitudes and are the locations of strong and persistent upwelling. At middle latitudes light typically is not a limiting factor for primary productivity in the water column, except during winter. However, inorganic nutrients such as nitrate have the potential to strongly limit primary production in the ocean at middle latitudes, because mixing energy from atmospheric forcing is relatively weak, allowing thermal stratification to occur in the water column and providing a barrier to transport of essential nutrients from depth to the shallows where primary producers can benefit.. It is the persistent upwelling in eastern boundary currents that counters the effects of thermal stratification, supplying inorganic nutrients by bringing deeper water to the surface. The result is high rates of primary production during all seasons except winter, with consequent high secondary production at higher trophic levels. Apex predators such as pinnipeds and seabirds benefit from the strong rates of primary production, such that their populations are large, productive, and persistent. The most likely effect of increased input of solar radiation would be an increase in thermal stratification of the water column. The increase in light availability is not likely to produce positive effects on primary production rates because it is already apparent that light typically is not limiting productivity in middle latitude eastern boundary currents except during winter. Increased thermal stratification of the water column will reduce rates of upwelling, unless the increase in light availability has the secondary effect of intensifying the equatorward winds that drive upwelling. Without intensification of equatorward winds, upwelling rates will be reduced, thus diminishing the rate at which inorganic nutrients are brought to surface waters where light is available to drive photosynthesis and primary productivity. The results will be reduced rates of secondary production in coastal food webs, a reduction of food supply for apex predators, and a net reduction in the size and productivity of populations of pinnipeds, seabirds, and other top-level consumers. 3. Sea otters are known to be capable of porpoising (i.e., jumping clear of the water to breathe) while travelling, but appear to do so only rarely, probably in response to sudden and unexpected disturbances. In contrast, many other marine mammal species, including small cetaceans and pinnipeds, appear to porpoise routinely when travelling. Suggest an explanation for the less frequent use of porpoising

8 when sea otters are travelling, as compared to small cetaceans and pinnipeds (marked by Glenn VanBlaricom). Porpoising is most commonly seen in relatively small, highly streamlined marine mammals that have ecological or social incentives to travel long distances on a frequent schedule. Sea otters are seen to porpoise only infrequently, probably in response to relatively rare, extreme disturbances that produce a fright-driven, energetically costly flight from the area of disturbance. Efficient porpoising requires the ability to swim efficiently at high enough speed to break free of the water surface for breathing purposes, and adequate streamlining to allow brief but efficient gliding and physiological recovery from a leap above the water, without a drastic loss of forward velocity. Sea otters lack many of the anatomical features that facilitate efficient porpoising in other species. Rear limbs are present is sea otters but lack the extreme streamlining seen in the small cetaceans and the more modest but nevertheless effective streamlining seen in pinnipeds that regularly porpoise when travelling. Sea otters also have a dense pelage, required for effective thermoregulation but probably the source of increased surface drag, as compared to porpoising pinnipeds and small cetaceans, when travelling underwater. Thus, it is likely that the cost of porpoising is higher for sea otters than for species that porpoise regularly, to the point that porpoising is not generally feasible. It is also important to recognize that sea otters generally face a less pressing incentive to travel frequently to obtain food. Sea otter prey are primarily benthic invertebrates with limited mobility, normally associated with specific nearshore habitats such as kelp forests or mudflats. The prey populations and the habitats they utilize generally are fixed in space, and are much more predictably available that the prey populations that sustain many species of pinnipeds and small cetaceans. Thus, sea otters do not have the strong incentive to move frequently to locate food. As a result, selection over evolutionary time scales likely has not favored the level of locomotive efficiency that is required of most pinnipeds and small cetaceans, and that has produced the ability to porpoise effectively. 4. What kinds of analyses would you conduct in order to understand the sharp decline in individually identifiable western gray whales in the Piltun feeding area, Russian Far East, during summer and autumn 2008, as compared to the previous four years? In your response, describe analyses involving data collected during 2008 and before, as well as data collection and analyses you would plan for the next three summer/autumn whale foraging seasons (2009 through 2011).

9 No one in the 2009 class elected to respond to question #4. Therefore, no key is provided in the interest of saving this question for possible use on a future examination. Synopsis of examination statistics: Number of students completing the examination: 47 Total possible points on the examination: 100 Mean score: 83 Median score: 83 Range of scores: Distribution of scores: 51-60: : : : : 12