Publisher Summary This chapter discusses the genetics of management, which helps in designing strategies to protect human impacted marine mammals. The advantage of genetic analyses is that data are easier to collect and few constraints are put on the quality of a sample or its origin. DNA is a relatively tough molecule, and adequate samples can be obtained from tiny amounts of a variety of tissues such as skin, blood or bloodstains, hair follicles, placenta, excrement, baleen, modern or ancient bone, or in some circumstances, formalin-preserved tissues. For instance, adequate amounts of mtDNA from ca . 1000-year-old bowhead whale ( Balaena mysticetus ) bones have been obtained. More recent historical samples of bone and baleen from St. Lawrence Island in the Bering Sea have been used for both mtDNA and SNP analysis. Management-oriented genetic studies use primarily (1) genotypes from microsatellite loci within the 3×10 9 or so base pairs (bp) of the mammalian nuclear genome or (2) DNA sequence data from a portion of the 1.6×10 4 bp of the mitochondrial genome; the subsequence is also known as a haplotype. Mitochondrial (mt) DNA is a multicopy, circular, cytoplasmic DNA that in marine mammals is inherited intact from the mother. In contrast, microsatellites are part of the nuclear genome and are inherited biparentally.

Current information is reviewed that provides clues to the intraspecific structure of dolphin species incidently killed in the yellowfin tuna purse-seine fishery of the eastern tropical Pacific (ETP) . Current law requires that management efforts are focused on the intraspecific level, attempting to preserve local and presumably locally adapted populations. Four species are reviewed: pantropical spotted, Stenella attenuata; spinner, S. longirostTis; striped, S. coeruleoalba; and common, Delphinus delphis, dolphins. For each species, distributional, demographic, phenotypic, and genotypic data are summarized, and the putative stocks are categorized based on four hierarchal phylogeographic criteria relative to their probability of being evolutionari ly significant units. For spotted dolphins, the morphological similarity of animals from the south and the west argues that stock designations (and boundaries) be changed from the current northern offshore and southern offshore to northeastern offshore and a combined western and southern offshore. For the striped dolphin, we find little reason to continue the present division into geographical stocks. For common dolphins, we reiterate an earlier recommendation that the long-beaked form (Baja neritic) and the northern short-beaked form be managed separately; recent morphological and genetic work provides evidence that they are probably separate species. Finally, we note that the stock structure of ETP spinner dolphins is complex, with the white belly form exhibiting characteristics of a hybrid swarm between the eastern and pantropical subspecies. There is little morphological basis at present for division of the whitebelly spinner dolphin into northern and southern stocks. However, we recommend continued separate management of the pooled whitebelly forms, despite their hybrid / intergrade status. Steps should be taken to ensure that management practices do not reduce the abundance of easte rn relative to whitebelly spinner dolphins. To do so may lead to increased invasion of the eastern's stock range and possible replacement of the eastern spinner dolphin genome. Management of dolphins incidentally killed in the purse seines of the eastern tropical Pacific (ETP) yellowfin tuna fishery is directed at the stock or population level. Realistic stock delineations are necessary both for estimating the impact of the fishery on dolphin species and for ensuring conservation of locally adapted genetic variation. Incidental mortality has primarily affected four species of dolphins, listed in order of exploitation (DeMaster et aI. , 1992): the pantropical spotted dolphin, Stenella attenuata; the spinner dolphin, S. longirostris; the common dolphin , Delphinus delphis; and the striped dolphin, S. coeruleoalba. Over the years, two Status ofPorpoise1 Stocks (SOPS) workshops have been convened to review the status of the impacted stocks (Anon.2; Smith3). In 1983, for a planned third workshop, Perrin et al. (1985) prepared a review of evi1 Convention in the fishing community uses the term "porpoise" for dolphin. 2 Anon. 1976. Report of the workshop on stock assessment of porpoises involved in the eastern Pacific ye llowfin tuna fishery. Southwest Fisheries Center, National Marine Fisheries Service, NOAA, Admin. Rep. LJ-76-29, 53 p. 3 Sm ith , T. D. 1979. Report of the status of porpoise stocks workshop (August 27-31, 1979, La Jolla, Cali fornia). Southwest Fisheries Center, National Marine Fisheries Service, NOAA, Admin. Rep. LJ-79-41, 120 p. 4 Although panels of experts were convened to review com ponents of the assessment, including stock identity, the fu ll work-

We report the characterization of 18 new single nucleotide polymorphism (SNP) markers for an endangered species, the sperm whale (Physeter macrocephalus), developed using a targeted gene approach. SNP markers were derived from autosomal regions of the genome using primers originally characterized for genome mapping in other mammals. These SNP markers are the first to be designed for genotyping sperm whale populations and will provide a necessary addition to the genetic tools employed for understanding population structure on a global scale and for developing a conservation management strategy for this endangered species.

Mitochondrial DNA (mtDNA) control region sequences and microsatellite loci length polymorphisms were used to investigate genetic differentiation in spotted dolphins (Stenella attenuata) in the Eastern Tropical Pacific and to examine the intraspecific structure of the coastal subspecies (Stenella  attenuata  graffmani). One-hundred and thirty-five animals from several coastal areas and 90 offshore animals were sequenced for 455 bp of the mitochondrial control region, resulting in 112 mtDNA haplotypes. Phylogenetic analyses and the existence of shared haplotypes between the two subspecies suggest recent and/or current gene flow. Analyses using χ2, F ST (based on haplotype frequencies) and ΦST values (based on frequencies and genetic distances between haplotypes) yielded statistically significant separation (randomized permutation values P<0.05) among four different coastal populations and between all but one of these and the offshore subspecies (overall F ST=0.0691). Ninety-one coastal animals from these four geographic populations and 50 offshore animals were genotyped for seven nuclear microsatellite loci. Analysis using F ST values (based on allelic frequencies) yielded statistically significant separation between most coastal populations and offshore animals, although no coastal populations were distinguished. These results argue for the existence of some genetic isolation between offshore and inshore populations and among some inshore populations, suggesting that these should be treated as separate units for management purposes.

Most fishes are poikilothermic-Le. their body temperature is within a few degrees of ambient unless ambient is changing rapidly. The exceptions are certain sharks and true tunas. Little is known about the locomotion and energetics of warm-bodied sharks. Our review focuses on a few species of tunas but draws on information from other fish (especially salmonids) to fill in the gaps in our understanding. Of interest here is a measure of the metabolic cost of producing known amounts of work per unit time; but there are problems with both sides of this equation, especially in the aquatic environment. Webb (30) has used a scheme similar to that in Figure 1 to show how total metabolic costs are partitioned. Since this approach is appropriate for sustained swimming in steady-state (i.e. oxygen supply keeping up with demand), especially when experiments are performed for short periods (hours), it is used here. Energy input or metabolic cost has been successfully estimated by measuring oxygen uptake and calories ingested. We focus our discussion on estimates based on these measurements. Other techniques for measuring metabolic costs have either been tried unsuccessfully or are yet to be tried. For example, few measurements have been made of C 0 2 production in fish (15, 16) and none for tuna. Knowledge of heat exchange rates and excess temperature has permitted some specula-

Stock structure of geographic forms of the spinner dolphin (Srenellu longirosrris) in the eastern tropical Pacific (ETP) is a conservation issue. These animals are incidentally killed during yellow fin tuna purse seining by US and international fleets, and mortality quotas apportioned by stock have been established by legislative act. Four management stocks of spinner dolphins in the ETP are currently defined on the basis of morphology and geographical distribution. However, recent work proposes that two of the stocks (the northern and southern 'whitebelly' spinners) comprise a broad zone of hybridisation or clinal integration between the neighbouring endemic 'eastern' spinner and the more typical spinners residing to the west and around the world in the tropics. I f this hypothesis is true. evidence of current or recent gene flow between the neighbouring 'stocks' should be apparent. To investigate this, we conducted a molecular analysis of mitochondrial DNA (mtDNA) extracted from livers of 151 spinner dolphins from the ETP and 13 spinner dolphins from the Timor Sea. We also analysed mtDNA from 10 spotted dolphins from the ETP. Liver mtDNA from each animal was digested with six restriction enzymes to deduce the individual mtDNA haplotypes. Genetic distances were then inferred within the sample pool by comparison of the individual mtDNA haplotypes in a pair-wise fashion. The results suggest the following three points: (1) The morphologically defined neighbouring eastern forms of ETP whitebelly spinners are not genetically distinct at the level of resolution of our analysis. We found no concordance of mtDNA haplotype with either the stock type of the school or individual morphology. The mean between-form distance was not significantly different from the two mean within-form distances. Thus, introgression is likely occurring (or has recently occurred) and significant genetic interchange can be inferred. (2) Mean within-school mtDNA diversity varied from school to school. and no clustering of certain haplotypes within specific schools was detected. (3) Timor Sea spinner and the spotted dolphins have unique mitochondrial genotypes likely characteristic of their geographic and genetic separation in the case of the spinner dolphins and their speeics-level separation in the case of the spotted dolphins. These findings reinforce the morphologically-based hypothesis of non-uniqueness of the whitebelly form and suggest that relatively more emphasis should be placed on conservation of the endemic and presumably locally adapted eastern form.

For many years, researchers have speculatedthat fin whales are year-round residents in theSea of Cortez (= Gulf of California). Previouswork by Bérubé and co-workers has shownthat the degree of genetic diversity among finwhales in the Sea of Cortez at nuclear andmitochondrial loci is highly reduced. However,the relatively unobstructed connection with theNorth Pacific Ocean argues that Sea of Cortezfin whales are part of a much larger easternNorth Pacific population given the extensivemigratory ranges observed in fin whales andbaleen whales in general. The low degree ofgenetic variation might thus simply be due tohistoric fluctuations in the effectivepopulation size of an eastern North Pacificpopulation. In order to test if the reducedgenetic variation detected among fin whales inthe Sea of Cortez is due to small populationsize or a past bottleneck in an otherwise largeeastern North Pacific population, we analyzedthe geographic distribution of geneticvariation at a single mitochondrial (controlregion) and 16 nuclear loci in samplescollected from fin whales in the eastern NorthPacific (n = 12) as well as the Sea of Cortez(n = 77). Our results showed that fin whalesobserved in the Sea of Cortez constitute ahighly isolated and thus evolutionary uniquepopulation, which warrants special conservationmeasures given the current low estimate ofabundance of approximately 400 individuals.

H. Whitehead (1) explains low nucleotide diversities in the control region of the mitochondrial DNA (mtDNA) of matrilineal whale species with the use of a theory developed for molecular “hitchhiking,” in which diversity at a neutral locus is reduced by selection at a linked locus. As appealing as this idea is, we question the strength of the evidence presented to support a connection between whale culture and genetic variation. In the proposed model [figure 1 in (1)], if nonmatrilineal transmission is greater than 0.5%, then mtDNA diversity is little reduced [figure 1D in (1)]. We agree that killer whales, pilot whales, and sperm whales show the best evidence for matrilineal social structure (2), yet even in these species the parameters of the model are likely not met. This is especially so in the case of sperm whales, where recent studies show that sperm whale units (3) and groups (4) are composed of both related and unrelated individuals, at numbers significantly above the 0.5% threshold (1) at which mtDNA diversity is little reduced. If unrelated individuals co-occur within a group, then the cultural transmission of advantageous information must be done in such a way that members outside a particular matriline are not privy to it. The model is presented to demonstrate the feasibility of a cultural trait that devastates mtDNA diversity. After such a trait sweeps through the population, molecular diversity should regenerate. Even if continual cultural innovation suppresses regeneration of diversity within geographic populations, one would not expect divergence among isolated populations to remain low. A good example of this problem would be short-finned pilot whales, whose distribution is generally thought to be restricted to warm waters. It is difficult to imagine selective sweeps, cultural or otherwise, acting to maintain low inter-ocean diversity. To us, the finding of low interocean mtDNA diversity suggests continuing selection. The data summarized to support the report’s hypothesis [table 1 in (1)] deserve close scrutiny. In comparative studies, it is necessary that the playing field be level. Samples need to be collected over comparable scales (geographic, temporal, and numerical), which is no trivial task in ocean-dwelling species. Moreover, the unsettled nature of cetacean alpha level taxonomy affects our ability to accurately compare estimates of molecular diversity across taxa. For example the “killer whale” and the “bottlenose dolphin” are names given to what we now understand to be complexes comprised of genetically distinct inshore and offshore taxa and suggested to be separate species (5). Table 1 in the report may be presenting diversity levels calculated both within species and within genera. There is strikingly low control region diversity in some cetacean species, all the more remarkable given the vast geographic ranges of these animals. With the above concerns in mind, we advocate the investigation of a more general question: What factors could reduce mtDNA diversity in whales, and how does their marine existence affect this pattern? Sarah L. Mesnick Barbara L. Taylor Richard G. Le Duc Sergio Escorza Treviño Greg M. O’Corry-Crowe Andrew E. Dizon Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanographic and Atmospheric Administration, La Jolla, CA 92038, USA E-mail: sarahlyn@caliban.ucsd.edu

Understanding the influence of social organisation on the distribution, abundance and genetic structure of cetacean populations is critical in developing better predictive models for management. Field data on cetacean social organisation are far more valuable when collected and analysed together with genetic data from biopsy samples and environmental information (e.g. oceanographic patterns, prey availability). Traditionally, however, studies of cetacean social behaviour and studies of cetacean population dynamics have been conducted independently (Tillman and Donovan, 1986). To integrate these fields, this paper recommends that multi-disciplinary cetacean assessment surveys collect biopsy and associated behavioural data for each sample taken (the minimum data being group size, number of animals biopsied and age class). Examples of sampling forms, outlining the desired information, are provided. Understanding of cetacean stock structure and the processes affecting stock differentiation will best come from a combined genetic, social, ecological and oceanographic approach.

Current information is reviewed that provides clues to the intraspecific structure of dolphin species incidently killed in the yellowfin tuna purse-seine fishery of the eastern tropical Pacific (ETP). Current law requires that management efforts are focused on the intraspecific level, attempting to preserve local and presumably locally adapted populations. Four species are reviewed: pantropical spotted, Stenella attenuata; spinner, S. longirostTis; striped, S. coeruleoalba; and common, Delphinus delphis, dolphins. For each species, distributional, demographic, phenotypic, and genotypic data are summarized, and the putative stocks are categorized based on four hierarchal phylogeographic criteria relative to their probability of being evolutionarily significant units. For spotted dolphins, the morphological similarity of animals from the south and the west argues that stock designations (and boundaries) be changed from the current northern offshore and southern offshore to northeastern offshore and a combined western and southern offshore. For the striped dolphin, we find little reason to continue the present division into geographical stocks. For common dolphins, we reiterate an earlier recommendation that the long-beaked form (Baja neritic) and the northern short-beaked form be managed separately; recent morphological and genetic work provides evidence that they are probably separate species. Finally, we note that the stock structure of ETP spinner dolphins is complex, with the whitebelly form exhibiting characteristics of a hybrid swarm between the eastern and pantropical subspecies. There is little morphological basis at present for division of the whitebelly spinner dolphin into northern and southern stocks. However, we recommend continued separate management of the pooled whitebelly forms, despite their hybrid/intergrade status. Steps should be taken to ensure that management practices do not reduce the abundance of eastern relative to whitebelly spinner dolphins. To do so may lead to increased invasion of the eastern's stock range and possible replacement of the eastern spinner dolphin genome.(PDF file contains 24 pages.)

One of the assumptions of line transect sampling is that movement of animals being counted is not in response to the approaching vessel before the animals are detected (Burnham et al. 1980). By observing from a helicopter the reaction of dolphins to an approaching survey vessel, Au and Perryman (1982) and Hewitt (1985) demonstrated that dolphin schools can detect the approach and maneuver to attempt to avoid detection. Because it may be that dolphin exhibit forms of optimal behavior (Au and Weihs 1980), it is of interest to determine whether there is a direction the dolphin should take that maximizes their distance to the vessel at the point of closest approach and, if there is such a direction, to determine whether dolphin use it. If this is so, this may be the way of determining through aerial means when dolphin first react to an approaching vessel and whether it is after they are detected by a shipboard observer. Since the advent of purse-seine fishing in the eastern tropical Pacific in 1959, dolphin that associate with yellowfin tuna (Le., primarily Stenella attenuata, S. longirostris, and Delphinus delphis) are chased,

DNA clones have been isolated that span the complete mitochondrial (mt) genome of the dolphin, Cephalorhynchus commersonii. Hybridization experiments with purified primate mtDNA probes have established that there is close resemblance in the general organization of the dolphin mt genome and the terrestrial mammalian mt genomes. Sequences covering 2381 bp of the dolphin mt genome from the major noncoding region, three tRNA genes, and parts of the genes encoding cytochrome b, NADH dehydrogenase subunit 3 (ND3), and 16S rRNA have been compared with corresponding regions from other mammalian genomes. There is a general tendency throughout the sequenced regions for greater similarity between dolphin and bovine mt genomes than between dolphin and rodent or human mt genomes.

Several difficulties arise when attempts are made to characterize the deposits of magnetite found in metazoans. We are usually forced to deal with very small amounts of material, dispersed in tissues, using indirect methods that are subject to contamination. Magnetite crystals in the abdomens of bees (Gould et al., 1978), and in the heads of pigeons (Walcott et al., 1979), and other vertebrates (Bauer et al., this volume; Perry et al., this volume; Walker et al., this volume) are submicroscopic (<100 nm), occupy a combined volume of 10−10 to 10−8 cm3, and have a mass of 1–100 ng. In organisms of up to 100 kg or more, detecting such quantities of magnetite from its magnetic properties depends on the crystals being highly concentrated in small, recognizable structures, and not uniformly dispersed throughout all the tissues. Extraction and recovery of the crystals likewise depend on their being sufficiently concentrated to be magnetically detectable.

An inexpensive and simple, remote-control conveyor-belt feeder is described. The feeder handles liquids and wet or dry solids.