Marine Mammal Science 

About: Marine Mammal Science is an academic journal published by Wiley. The journal publishes majorly in the area(s): Cetacea & Population. It has an ISSN identifier of 0824-0469. Over the lifetime, 2683 publications have been published receiving 87079 citations.

Calculating limits to the allowable human‐caused mortality of cetaceans and pinnipeds

Abstract: A simulation method was developed for identifying populations with levels of human-caused mortality that could lead to depletion, taking into account the uncertainty of available information. A mortality limit (termed the Potential Biological Removal, PBR, under the U. S. Marine Mammal Protection Act) was calculated as the product of a minimum population estimate (NMIN), one-half of the maximum net productivity rate (RMAX), and a recovery factor (FR). Mortality limits were evaluated based on whether at least 95% of the simulated populations met two criteria: (1) that populations starting at the maximum net productivity level (MNPL) stayed there or above after 20 yr, and (2) that populations starting at 30% of carrying-capacity (K) recovered to at least MNPL after 100 yr. Simulations of populations that experienced mortality equal to the PBR indicated that using approximately the 20th percentile (the lower 60% log-normal confidence limit) of the abundance estimate for NMIN met the criteria for both cetaceans (assuming RMAX= 0.04) and pinnipeds (assuming RMAX= 0.12). Additional simulations that included plausible levels of bias in the available information indicated that using a value of 0.5 for FR would meet both criteria during these “bias trials.” It is concluded that any marine mammal population with an estimate of human-caused mortality that is greater than its PBR has a level of mortality that could lead to the depletion of the population. The simulation methods were also used to show how mortality limits could be calculated to meet conservation goals other than the U. S. goal of maintaining populations above MNPL.

Studying trophic ecology in marine ecosystems using fatty acids: a primer on analysis and interpretation

Abstract: Fatty acids (FA) represent a large group of molecules that comprise the majority of lipids found in all organisms. Their great diversity, biochemical restrictions and, in some cases, unique origin among plants and animals has fostered a number of areas of research, ranging from assessment of animal nutrition and metabolism, to investigating trophic interactions and ecosystem structure. Over the past three decades, we have observed the use of FA develop from a potential tool for delineating food webs (Ackman and Eaton 1966) to a powerful technique for quantitative assessment of predator diets (Iverson et al. 2004). Studies that have compared the FA found in predator fat stores with those found in their prey have allowed both qualitative (e.g., Horgan and Barrett 1985; Smith et al. 1996; Raclot et al. 1998; Dahl et al. 2000, 2003; Falk-Petersen et al. 2004) and quantitative or semi-quantitative analyses of diet (Kirsch et al. 2000; Iverson et al. 2001b, 2004; Iverson and Springer 2002) and

Using stable isotope biogeochemistry to study marine mammal ecology

Abstract: Stable isotope analysis (SIA) has emerged as a common tool in ecology and has proven especially useful in the study of animal diet, habitat use, movement, and physiology. SIA has been vigorously applied to the study of marine mammals, because most species live in habitats or undergo large migrations/movements that make them difficult to observe. Our review supplies a complete list of published SIA contributions to marine mammal science and highlights informative case examples in four general research areas: (1) physiology and fractionation, (2) foraging ecology and habitat use, (3) ecotoxicology, and (4) historic ecology and paleoecology. We also provide a condensed background of isotopic nomenclature, highlight several physiological considerations important for accurate interpretation of isotopic data, and identify research areas ripe for future growth. Because it is impossible to conduct controlled laboratory experiments on most marine mammal species, future studies in marine mammal ecology must draw on isotopic data collected from other organisms and be cognizant of key assumptions often made in the application of SIA to the study of animal ecology. The review is designed to be accessible to all audiences, from students unfamiliar with SIA to those who have utilized it in published studies.

Collisions between ships and whales

Abstract: Although collisions with motorized ships are a recognized source of whale mortality, little has been done to compile information on the frequency of their occurrence or contributing factors. We searched historical records and computerized stranding databases for evidence of ship strikes involving great whales (i.e., baleen whales and the sperm whale). Historical records suggest that ship strikes fatal to whales first occurred late in the 1800s as ships began to reach speeds of 13-15 kn, remained infrequent until about 1950, and then increased during the 1950s-1970s as the number and speed of ships in­ creased. Of 11 species known to be hit by ships, fin whales (Balaenoptera physalus) are struck most frequently; right whales (Eubalae1la glacialis and E. allStralis), humpback whales (Megaptera novaeangliae), sperm whales (Physeter catodon), and gray whales (Eschrichtius robustllS) are hit commonly. In some areas, one-third of all fin whale and right whale strandings appear to involve ship strikes. To assess contributing factors, we compiled descriptions of 58 collisions. They indicate that all sizes and types of vessels can hit whales;

Behavioral sampling methods for cetaceans: a review and critique

Abstract: Behavioral scientists have developed methods for sampling behavior in order to reduce observational biases and to facilitate comparisons between studies. A review of 74 cetacean behavioral field studies published from 1989 to 1995 in Marine Mammal Science and The Canadian Journal of Zoology suggests that cetacean researchers have not made optimal use of available methodology. The survey revealed that a large proportion of studies did not use reliable sampling methods. Ad libitum sampling was used most often (59%). When anecdotal studies were excluded, 45% of 53 behavioral studies used ad libitum as the predominant method. Other sampling methods were continuous, onezero, incident, point, sequence, or scan sampling. Recommendations for sampling methods are made, depending on identifiability of animals, group sizes, dive durations, and change in group membership.