Waldick, R. C.; S. Kraus; M. Brown and B. N. White.
Evaluating the effects of historic bottleneck events: An assessment of microsatellite variability in the endangered North Atlantic right whale.
Molecular Ecology 11(11):2241-2249.
Commercial exploitation reduced the North Atlantic right whale (Eubalaena glacialis) population from c. 12 000 in the 11th century to around 300 by the 21st century. We examine the effect of this population decline on levels of genetic variation at 16 microsatellite loci and contrast levels of variability to that in a closely related species (E. australis). Of the 13 loci developed from the E. glacialis genome, 100% were polymorphic in E. australis. In contrast, nine loci were polymorphic in E. glacialis and four were fixed. Both allelic diversity (A) and heterozygosity (H) were significantly lower in E. glacialis than E. australis (A = 3.2 ±± ± ± 2.6 vs. A = 6.9 ±± ± ± 3.3, P < 0.001; H = 0.31 ±± ± ± 0.25 vs. H = 0.72 ±± ± ± 0.23, P < 0.001, respectively). Bottleneck anlayses indicate that the population is in mutation-drift equilibrium and that a genetic bottleneck did not occur during the most recent decline (18th - 20th centuries). Nevertheless, low frequency alleles are relatively uncommon in E. glacialis, suggesting that genetic variability has been reduced in this population. Possible origins of low genetic variability are discussed, including the slow but continual erosion of alleles during the 800-year period of decline.

Barco, S. G., W. A. McLellan, J. M. Allen, R. A. Asmutis-Silvia, R. Mallon-Day, E. M. Meagher, D. A. Pabst, J. Robbins, R. E. Seton, W. M. Swingle, M. T. Weinrich and P. J. Clapham.
Population identity humpback whales (Megaptera novaeangliae) in the waters of the US mid-Atlantic states.
Journal of Cetacean Research and Management 4(2): 135-141.
In recent years, humpback whales (Megaptera novaeangliae) have been observed in the waters of the US mid-Atlantic states (USMA; New Jersey to North Carolina ), notably in winter. The level of the mortality in this area (52 recorded deaths from 1990-2000), makes it important to understand the nature and population identity of this aggregation. Of the approximately 100 humpback whales documented in this study, photographs of 41 (live or dead) were of sufficient quality to be compared to catalogues from the Gulf of Maine (GOM, the closest feeding ground) and elsewhere in the North Atlantic . Of 22 live whales, 10 (45.5%) matched to the GOM, 5 (22.7%) to Newfoundland and 1 (4.5%) to the Gulf of St Lawrence (GSL). Of 19 dead whales, 6 (31.6%) were known GOM whales. Although the population composition of the USMA is dominated by GOM whales, lack of recent photographic effort in Newfoundland makes it likely that the observed match rates under represent the true presence of Canadian whales in the region. Length data from 48 stranded whales (18 females, 22 males and 8 of unknown sex) suggest that 39 (81.2%) were first-year animals, 7 (14.6%) were immature and 2 (4.2%) were adults. However, sighting histories of five of the dead whales indicate that some were small for their age and histories of live whales further indicate that the population contains a greater percentage of mature animals than is suggested by the stranded sample. The authors suggest that the study area primarily represents a supplemental winter feeding ground that is used by humpbacks for more than one purpose. From a management perspective, although the only successful matches of mortalities to date have been to the GOM, the observed mixing of live whales from different summer stocks might suggest that the high numbers of mortalities occurring there may not be impacting this single stock alone. Although further data are required before conclusions can be drawn, the mortality rate may be significant for the GOM population and this warrants further investigation.

Wiley, D.N.*, G. Early, C.A.Mayo, and M.J. Moore.
"Rescue and release of mass stranded cetaceans from beaches on Cape Cod, Massachusetts, USA; 1990-1999: a review of some response actions."
Aquatic Mammals 27(2): 162-171.
Responses to aid mass stranded cetaceans are hampered by a lack of scientific guidance and shared experience. In this paper, we provide a qualititative and quantitative review of 17 selected mass stranding events that occurred on Cape Cod , Massachusetts , USA , and the responses taken to aid the animals. Three hundred and seventy-six animals were involved in the strandings. Most (n=299) were euthanized or otherwise died without rescue being attempted. We made concerted rescue efforts for 77 animals; 53 pilot whales (Globicephala melas), 16 white-sided dolphins (Lagenorhynchus acutus), and 8 common dolphins (Delphinus delphis). Rescue efforts did not include captive rehabilitation. Results from these attempts indicated that: 1) species involved could survive being transported to release sites up to 40 km away from the original site of stranding (90% survival, n=41), 2) previously stranded animals did not habitually restrand after release (82% not observed to restrand, n=73), and 3) rapidly obtained qualitative data could identify animals that did not restrand (91% not observed to restrand, n=24). Sixty of 77 animals, 78% survived transport and were released withou restranding, or were released from the stranding site without restranding. We did not carry-out long-term studies to determine the ultimate survival or death of animals that were not observed to restrand. However, documentation of short-term survival is needed prior to undertaking expensive, long-term investigations. We also used the entire database to investigate the effect of season on stranding events. The number of stranding events did not vary by season, but group size was larger in the winter (G^2=54.6, df=2, P<0.01). There were also significant differences in the seasonal mortality rates of stranded animals. Mortality rates were: winter (0.96+-0.01, n=233), spring (0.79+-0.05, n=68), and fall (0.52+-0.06, n=71). Summer was excluded due to small sample size. Data suggest that rapid intervention by well-trained and equipped response personnel can increase the chance that animals will survive the stranding event, and that long-term studies of survivorship are advisable.

Robbins, Jooke.
A review of scientific contributions from commercial whalewatching platforms.
Working paper of the Scientific Committee of the International Whaling Commission. SC/52/WW9. 11 pp.
A literature review was performed to evaluate the contribution of whalewatching-based programs to the present scientific understanding of cetacean populations. Peer-reviewed publications were identified through systematic, bibliographic searches of English-language journals, information gathered from gray literature and word-of-mouth. The review was limited to studies in which data collection was incidental to commercial whalewatching activities. Research ecotourism, in which paying passengers or volunteers assisted in scientifically directed cruises (e.g. Earthwatch), was not included. Sixty-two refereed publications were based largely or entirely on commercial whalewatching data. Although humpback whales, Megaptera novaeangliae, were best represented, a total of seven mysticete and five odontocete species were studied. Publications addressed a wide range of topics, including: distribution, stock identity, reproductive parameters, abundance, population composition, migratory destinations, behavior and human-related impacts. This review confirmed that, when carefully applied, data from whalewatching platforms have been a valuable resource to the scientific community. However, only five countries were represented in the peer-reviewed literature, and one region, the Gulf of Maine , was the focus of the majority of the published work. Thus, despite the high reported use of commercial platforms for research, the average published scientific contribution of whalewatching data remains low.

Robbins, J. and Mattila, D.K.
The use of commercial whalewatching platforms in the study of cetaceans: benefits and limitations.
Working paper of the Scientific Committee of the International Whaling Commission. SC/52/WW8. 7 pp.
Basic biological parameters can be difficult to measure in cetacean populations due to the extensive field effort required to amass necessary data. Commercial whalewatching operations perform daily excursions into prime whale habitats and therefore provide an opportunity to collect data at a frequency that is rarely feasible through directed research. These platforms have a wide variety of applications, but are particularly valuable in the accumulation of individual-specific data that are necessary to quantify biological parameters, such as reproductive rates. They may also serve as a valuable foundation for directed research by contributing data, like age, that can be difficult or impossible to acquire in the short-term. However, sampling biases and inefficiencies resulting from the commercial operation of a whalewatching platform can limit their usefulness, particularly over short time frames. Furthermore, the large volume of opportunistic data obtained can be costly to manage and use effectively. The most useful programs will therefore require a commitment of time and resources to sustain them in the long-term.

Finzi J., Mayo C., Lyman E., and Brown M.
The influence of prey patch structure on the distribution of right whales.
Abstract in the proceedings of the 13th Biennial Conference on the Biology of Marine Mammals. Maui, Hawaii. November 27 - December 3.
As in other taxa of grazing animals, the distribution of right whales, Balaena glacialis, in foraging areas appears to reflect the distribution of food resources. Thus, the primary factor influencing the occurrence of right whales is the distribution of patches of calanoid copepods that form seasonally in the shelf waters of the western North Atlantic. To investigate the factors controlling the distribution of right whales we mapped the co-occurrence of calanoid copepod patches and aggregations of feeding right whales and estimated a variety of patch characteristics that result in the aggregation or dispersion of the whales. The patches studied (n=4) ranged from 28 km2 to 42 km2 in surface area yielding a mean density of 1 whale in 3.6 + 1.9 km2. The patch persistence was estimated at 19+8.2 days, the mean total caloric content of the patch before grazing was 2.3x108 +0.7x108 kcal (of which 2.0x108 +0.6x108 kcal are estimated to be available to foraging whales), and an estimated mean consumption rate of 9.28 kcal sec-1 whale-1 or 5.51 x106kcal day-1 whale-1. From these estimates we propose a simple multi-scale model using empirically derived patch characteristics. The model demonstrates that at the medium scale (kilometers and days of resolution) the patches, and hence the whales, are most likely influenced by physical processes including advection and turbulence. On the fine scale (meters and hours) the structure of the patch is affected by both biological and physical processes.

Lyman E., Bowman B., Mattila D., Mayo C.A.
A technique for disentangling large free-swimming whales.
Abstract in the proceedings of the 13th Biennial Conference on the Biology of Marine Mammals. Maui, Hawaii. November 27 - December 3.
Entanglement in fishing gear has been identified as a source of serious injury and mortality among several species of cetaceans in the northwestern North Atlantic. In the case of the endangered North Atlantic right whale, Eubalaena glacialis, in which less than 350 animals are believed to exist, the successful release of just one animal may literally have a profound effect on the recovery of the population as a whole. In 1984 the Center for Coastal Studies ( CCS ) developed a technique for disentangling free-swimming, whales from life-threatening entanglements. The technique, a modification of an old whaling practice called "kegging", involves attaching large floats, "kegs", to the gear entangling the animal. The floats add buoyancy and drag to the animal making it difficult for it to dive, as well as, tiring it out. Once the whale slows down and spends more time at the surface, the rescue team approaches in a soft-bottom inflatable and cuts the whale free. Over the years, CCS staff has designed, created, and compiled numerous special tools for attaching to whales, and cutting them free, including: grapples, flying gaff hooks/ cutters, hooked knives, and sea anchors. In addition, the Center designed and created a special telemetry buoy, which can be attached to the entangling gear, for use when conditions prevent the animal from being completely disentangled on the first attempt. The buoy houses both satellite and VHF transmitters allowing the whale to be relocated, both remotely and in real time, for future rescue attempts when weather and resources allow. To date, CCS staff has successfully disentangled more than 45 whales that have become accidentally entangled in fishing gear. Disentanglement of large whales from fishing gear by trained, properly equipped personnel is currently the only effective method in reducing serious injury and mortality due to entanglements.

Mattila, D. K., J. Robbins, P.J. Clapham and P.J. Palsbøll.
Age, feeding ground origin and behavior of West Indies humpback whales, Megaptera novaeangliae.
Abstract in the proceedings of the 13th Biennial Conference on the Biology of Marine Mammals. Maui, Hawaii. November 27 - December 3.
Age, feeding ground origin and exchange between behavioral roles were examined on the West Indies wintering grounds for insight into the relative importance of presumed reproductive behaviors. During the two-year YONAH project, large photographic and genetic samples were collected throughout the North Atlantic using standardized methodologies. Data were correlated with behavioral observations in the West Indies and our long-term life history database from the Gulf of Maine (871 individuals, 224 known age). The age composition of the breeding aggregation was examined using 97 matches to catalogued Gulf of Maine whales. Eighty-two animals were sexually mature, nine were juveniles and six were of unknown maturational class. The average age of West Indies whales was significantly older than the YONAH sample in the Gulf of Maine . Among mature males, age did not vary significantly across behavioral roles, including within competitive groups, single escorts to mothers, singletons and pairs. Only one confirmed singer was of known age; however, exchange of 82 males between 175 roles during the same season also provided little evidence of a role-based hierarchy.; Only escorts (n=19) to mothers were resighted in the same role more often than expected.; As no females in our sample gave birth in consecutive years, a consistent preference to associate with mothers should reduce the likelihood of successful reproduction even more than previously supposed. In fact, when the high latitude origin of both animals was known, pairs without calves were from mixed feeding grounds (n=4), while escorts and the mothers they accompanied hailed from the same feeding ground (n=4). As males were not the father of the calves they escorted, our findings sugges a non-reproductive function. Additional data on the behavior and reproductive status of females in competitive groups sheds light on the function of these groups.

Mayo C.A.
The development and application of standards for assessing the quality of right whale habitat.
Abstract in the proceedings of the 13th Biennial Conference on the Biology of Marine Mammals. Maui, Hawaii. November 27 - December 3.
By developing a set of measures of habitat quality we establish criteria and standards for habitat assessment and management. We calculate a “feeding threshold” of 3,750 organisms m-3 or 0.52 kcal m-3 of capturable energy. From Lockyer (1981) we define a minimum caloric requirement or “caloric threshold” of 0.69 kcal m-3. To set a criterion for prey quality we assess the relative value of the 6 taxa of copepods by estimating the filterablility, caloric content per weight, and tendency to form dense micro patches. Finally we establish a measure of the biomass value of Cape Cod Bay by estimating the caloric content of the zooplankton of the whole bay and comparing that with the caloric content available in patches exceeding the caloric threshold.

The use of such habitat quality standards is demonstrated by assessing the quality of the zooplankton resource in the winter feeding habitat in the bay since 1984. The mean area of the habitat encompassed by surface patches rich enough to surpass the feeding threshold ranged from 3 to 58%. The surface area exceeding the caloric threshold varied from 2 to 38% with a mean of 19%.

Our demonstration of methods for measuring habitat quality establishes both the value of tracking habitat change through time and of establishing a baseline of habitat quality in critical right whale feeding areas being considered for management and conservation action.

Robbins, J. and D. K. Mattila.
A directed, photographic technique for estimating large whale entanglement rates.
Abstract in the proceedings of the 13th Biennial Conference on the Biology of Marine Mammals. Maui, Hawaii. November 27 - December 3.
Entanglement in fishing gear is a serious source of large whale injury and mortality. This impact has generally been monitored by detecting events as they occur or by studying injuries documented opportunistically in long-term photo-identification catalogs. Both approaches rely upon substantial effort and resources. Furthermore, biases in reporting and documentation can obscure the proportion of the population affected and changes in rates over time. The caudal peduncle is commonly implicated in large whale entanglements and, in some species, is presented consistently during the terminal dive. Through dedicated sampling and standard analysis, peduncle scarring can serve as a relative index of entanglement in species that fluke. During 1997 and 1998, high quality photographs were taken of the caudal peduncle of 217 free-ranging humpback whales, Megaptera novaeangliae, in the Gulf of Maine . Photographs were obtained while travelling parallel to the whale and slightly ahead of its flukes during the terminal dive. Images were blind coded to reflect the presence or absence of wrapping scars, notches and other injuries. The coding system was successfully tested against seven whales with documented entanglements in 1998. A minimum of 48% (n=64) of the 1998 sample had a high probability of previous caudal peduncle entanglement. Only 22% (n=30) exhibited no evidence of entanglement. Ten percent (n=3) of the individuals sampled in both years (n=31) acquired scars between events. However, the proportion carrying high probability scars did not differ significantly from 1997. Although non-calf juveniles (n=21) were at highest risk, whales remained susceptible as adults (n=138). Males (n=72) exhibited significantly higher rates of entanglement than females (n=116). By yielding large samples over short time frames, this technique can be used to evaluate the effectiveness of mitigation efforts in the short- and long-term. It is applicable to less well-studied populations, and standard methods facilitate comparison between populations and species.

Robbins, J. and Mattila, D.
"Monitoring entanglement scars on the caudal peduncle of Gulf of Maine humpback whales"
Report to the National Marine Fisheries Service. Order number 40ENNF800288.
Rates and risk factors associated with humpback whale entanglements were evaluated from a baseline photographic sample of the caudal peduncle. The caudal peduncle was selected for monitoring both because it plays a key role in humpback whale entanglements and because of the feasibility of obtaining large, unbiased photographic samples. Blind coding of scar patterns exhibited by 134 individuals in 1998 indicated that between 48% and 78% had experienced a previous entanglement. Although whales accumulated entanglement scars throughout their lives, juvenile whales and males appeared to be at higher risk. Ten percent of the individuals sampled in 1997 and 1998 acquired entanglement-related scars between years. However, only 2-3% of severe entanglement injuries appeared to be recent. The coding scheme used in this study accurately reflected the status of whales with documented 1998 peduncle entanglements, based solely on their scarring. With continued baseline sampling, this method would provide a useful way of evaluating the rates and severity of entanglement scarring over time.

Smith, TD, Allen, J, Clapham, PJ, Hammond, PS, Katona, S, Larsen, F, Lien, J, Mattila, D, Palsbøll, Sigurjónsson, J, Stevick, PT, Øien, N.
"An ocean-wide mark-recapture study of the North Atlantic humpback whale, Megaptera novaeangliae"
Marine Mammal Science. 15:1-32.
Although much is known about the humpback whale, Megaptera novaeangliae, regional studies have been unable to answer several questions that are central to the conservation and management of this endangered species. To resolve uncertainties about population size, as well as the spatial and genetic structure of the humpback whale population in the North Atlantic , we conducted a two-year ocean-basin-wide photographic and biopsy study in 1992-1993. Photographic and skin-biopsy sampling was conducted of animals in feeding and breeding areas throughout most of the range of this species in the North Atlantic , from the West Indies breeding grounds through all known feeding areas as far north as arctic Norway . A standardized sampling protocol was designed to maximize sample sizes while attempting to ensure equal probability of sampling, so that estimates of abundance would be as accurate and as precise as possible. During 666 days at sea aboard 28 vessels, 4,207 tail fluke photographs and 2,326 skin biopsies were collected. Molecular analyses of all biopsies included determination of sex, genotype using six microsatellite loci, and mitochondrial control region sequence. The photographs and microsatellite loci were used to identify 2,998 and 2,015 individual whales, respectively.

Previously published results from this study have addressed spatial distribution, migration, and genetic relationships. Here, we present new estimates of total abundance in this ocean using photographic data, as well as overall and sex-specific estimates using biopsy data. We identify several potential sampling biases using only breeding-area samples and report a consistent mark-recapture estimate of oceanwide abundance derived from photographic identification, using both breeding and feeding-area data, of 10,600 (95,70 confidence interval 9,300-12,100). We also report a comparable, but less precise, biopsy-based estimate of 10,400 (959o confidence interval of 8,00013,600). These estimates are significantly larger and more precise than estimates made for the 1980's, potentially reflecting population growth. In contrast, significantly lower and less consistent estimates were obtained using between-feeding-area or between-breeding-area sampling. Reasons for the lower estimates using the results of sampling in the same areas in subsequent years are discussed. Overall, the results of this ocean-basin-wide study demonstrate that an oceanwide approach to population assessment of baleen whales is practicable and results in a more comprehensive understanding of population abundance and biology than can be gained from smaller-scale efforts.

Stevick, P. T., N. Oien and D. K. Mattila.
Migratory destinations of humpback whales from Norwegian and adjacent waters: evidence for stock identity.
Journal of Cetacean Research and Management 1(2):147-152.
Migratory destinations of humpback whales (Megaptera novaeangliae) in the eastern North Atlantic were investigated using natural markings. A total of 96 individuals was identified from Norwegian and adjacent waters during 1992 and 1993: of these 63 were observed in the Norwegian and Barents Seas and 33 in the Greenland Sea near Jan Mayen. These were compared with other individuals identified throughout the North Atlantic to identify re-sightings. Ten individuals were identified in both Norway and in the West Indies . There were no significant differences in this West Indies exchange rate between the sample from Norway or either Norwegian sub-area and any other feeding area in the North Atlantic. The mean West Indies sighting date for humpback whales from Norway was 2 March, significantly later than the overall means for sightings from the West Indies. The individuals identified represent a variety of reproductive classes and both sexes. Observations of mothers with newborn calves, and males in competitive groups, provide the strongest evidence to date that the West Indies is utilized as a breeding and calving ground by humpback whales which feed in Norwegian waters. These results suggest that the West Indies is an important, and likely the primary, breeding destination for individual humpback whales feeding off Norway.

Trull, P., Heckew S., Watson M.J. & Nisbet I.C.T.
“Staging of Roseate Terns Sterna Dougallii in the Post-Breeding Period around Cape Cod, Massachusetts, USA ”
We conducted several studies of Roseate Terns Sterna dougallii around Cape Cod , Massachusetts , USA , during the post-breeding period (July-September) in 1990-1998. We also reviewed reports and estimates of numbers in regional publications. We identified 20 discrete sites where Roseate Terns and Common Terns S. hirundo staged (rested in flocks during daylight hours) between 24 July and 22 September. All sites were on open beaches or sandflats, usually near the end of barrier islands or barrier beaches. Only one site was found where Roseate Terns were present in thousands, but three other such sites have been documented during the last 20 years. All of these major staging sites are on outer beaches of Cape Cod adjacent to cold Atlantic Ocean waters. Roseate Terns appear to disperse throughout the breeding area in July and August, re-aggregating on outer Cape Cod in late August and September prior to southward migration in mid-September. Roseate Terns ringed at eight colony-sites throughout the breeding area in north-eastern North America were identified at staging sites around Cape Cod . We found only two sites on Cape Cod where Roseate Terns roosted at night in 1998; one of these has been a major roost site for many years. The concentration of a large fraction of this endangered regional population into a small area during September makes it vulnerable to human disturbance (especially at night) and to North Atlantic hurricanes.

Palsbøll, P, Allen,J, Bérubé, M, Clapham, PJ, Feddersen, TP, Hammond, PS, Hudson, RR, Jorgensen, H, Katona, S, Larsen-Holm, A, Larsen, F, Lien, J, Mattila, DK, Sigurjónsson, J, Sears, R, Smith, T, Sponer, R, Stevick, P, Oien, N.
"Genetic tagging of humpback whales"
Nature. 388:767-769.
The ability to recognize individual animals has substantially increased our knowledge of the biology and behaviour of many taxa. However, not all species lend themselves to this approach, either because of insufficient phenotypic variation or because tag attachment is not feasible. Since genetic "tags" are permanent and exist in all individuals, their use represents a viable alternative to traditional methods of individual recognition. We tested the use of genetic markers as the primary means of identifying individuals in a study of North Atlantic humpback whales. Analysis of six microsatellite loci among 3,060 skin samples collected throughout this ocean basin permitted unequivocal identification of individuals. Six hundred ninety-two "recaptures" (identified by their genotype) revealed individual local and migratory movements of up to 10,000 kilometers, limited exchange amongst summer feeding grounds and mixing in winter breeding areas; it also enabled the first estimates of animal abundance based solely on genotypic data. Our study demonstrates that genetic tagging is feasible and in addition generates data (e.g., on sex) that can be valuable when interpreting the results of tagging experiments.

Skin biopsy or sloughed skin samples from free-ranging humpbacks were collected across the North Atlantic between 1988 and 1995. Total-cell DNA was extracted and the sex as well as the genotype at six Mendelian inherited microsatellite loci was determined for each sample. Amongst the 3,060 samples analyzed we detected 2,368 unique genotypes. The expected number of samples collected from different individuals with identical genotype due to chance was estimated at less than one. Because of this, and the fact all samples with identical genotypes were of consistent sex, we inferred that the 3,060 samples represented 2,368 individual whales.

Murphy, MA.
"Occurrence and group characteristics of minke whales, Balaenoptera acutorostrata, in Massachusetts Bay and Cape Cod Bay "
Fishery Bulletin. 93:577-585.
The minke whale, Balaenoptera acutorostrata, is one of the smallest of the baleen whales. Despite exploitation by the whaling industry in recent years, comparatively little is known about the biology and behavior of this species. The minke has a cosmopolitan distribution, although recent biochemical studies suggesting large genetic differences between oceanic populations (Amos and Dover, 1991; Hoelzel and Dover, 1991; van Pijlen et al., 1991; Wada and Numachi, 1991; Wada et al., 1991) have cast some doubt on the long-held belief that all populations constitute a single species. As is the case for most baleen whales, minke whales appear to migrate to high latitudes in the summer for feeding and to travel to tropical waters in the winter for birthing (Horwood, 1989; Mitchell, 1991). However, specific breeding grounds have yet to be unequivocally identified, and it is unknown whether both sexes and all age classes in a population undertake the migration to low latitudes. In some temperate, subtropical, and tropical areas, minke whales are observed throughout the year (Ivashin and Votrogov, 1981; Best, 1982; Gong, 1987; Stern, 1990), although it is unclear whether these sightings represent year-round residency on the part of particular individuals or a moregeneral movement through the area by members of one or more populations.

In recent years, much has been learned about other mysticetes through long-term studies based on the identification of individual whales (see Hammond et al., 1990). Unfortunately, minke whales lack the great variability in natural markings that have facilitated detailed investigations of larger confamilials (such as humpback whales, Megaptera novaeangliae). This, together with the difficulty of photographing them owing to their small size and great speed, has hindered studies based on photographic identification, although studies of small localized populations have been possible (Dorsey, 1983; Dorsey et al., 1990; Stern et al., 1990). In general, however, studies of free-ranging minke whales have been few, and their population structure, social organization and migratory movements remain poorly understood.

Minke whales are commonly observed in the waters of Massachusetts Bay and Cape Cod Bay in New England , and since 1979, sightings of this species have been routinely recorded from both commercial whale-watching vessels and dedicated surveys. In this paper, sighting records are examined in an effort to describe the temporal distribution, seasonal abundance and feeding behavior of minke whales in this region. These data are then compared with information reported for this species from other areas, notably within the North Atlantic.

Mattila, DK, Clapham, PJ, Vasquez, O, Bowman, RS.
"Occurrence, population composition and habitat use of humpback whales in Samana Bay, Dominican Republic"
Canadian Journal of Zoology. 72:1898-1907.
A study of humpback whales (Megaptera novaeangliae) was conducted between 1988 and 1991 in Samana Bay, Dominican Republic. Humpbacks were observed as early as the earliest survey (3 January) and as late as the latest (16 March). Local abundance varied from 0 whales per hour to a maximum of 3.2 whales per hour (mean = 1.70, SD = 0.79), and densities calculated from track surveys ranged from 0.09 to 0.82 whales per square nautical mile (mean = 0.31). Abundance generally peaked in February, but variation was observed both within a season and between years. Almost all whales were observed in the eastern part of the bay, towards or at its mouth.

In all, 397 individuals were photographically identified during the study period. Of these, 18 were observed in more than 1 year (17 in 2 years, I in 3 years). A total of 15.8% of identified individuals were observed on more than 1 day in a year (maximum 5 days), with mothers representing 33.3 % of all resightings. Observed occupancies of resighted animals ranged from 1 to 33 days (mean = 6.3 days, SD = 7.14). The mean group size was 1.95 (range = I - 15, SD = 1.30, n = 652 groups). Ninety-nine groups contained a calf, and all -groups larger than three (n = 45) were competitive in nature. Comparisons of fluke photographs with the North Atlantic Humpback Whale Catalogue revealed 141 matches of 118 individuals to other areas. Of these, 76 were to high-latitude feeding grounds (including the Gulf of Maine, Newfoundland, Labrador, the Gulf of St. Lawrence, and west Greenland), while the remaining 65 were to other areas of the West Indies (Silver Bank, Navidad Bank, Puerto Rico, Virgin Bank, or Anguilla Bank) or to Bermuda. We suggest that Samana Bay is one of the most important winter habitats in the West Indies for humpback whales from all over the western North Atlantic , although whaling records suguest that the abundance of whales in this area may be a relatively recent phenomenon. Sightings of other marine mammal species in Samana Bay are summarized.

Clapham, PJ, Mattila, DK.
Reactions of humpback whales to skin biopsy sampling on a West Indies breeding ground.
Marine Mammal Science. 9(4):382-391.
Reactions of humpback whales, Megaptera novaeangliae, to the taking of skin biopsies and to associated activities were studied on one of their principal West Indies breeding grounds on Silver Bank ( Dominican Republic ). Results were in some cases different from those reported from a similar study ofthis species in a high-latitude feeding area. Almost half (44.1%) of 565 biopsied whales showed no immediate reaction to a hit, while a further 22.5%showed only low-level reactions. A total of 375 (87.8%) of 427 misses involved no reaction. Only one strong reaction was recorded. Behavior changes were recorded following 31 (5.5%) of 569 hits, and 18 (4.5%) of 404 misses. Evasive behavior related to vessel approach was exhibited prior to 72 (12.0%) of 598 hits and 100 (24.1%) of 415 misses.

Mothers showed significantly fewer reactions to hits than other whales, and a similar frequency and typeof behavior changes, although they tended to be more evasive before a shot was made. Presumed males in competitive groups also showed significantly fewer reactions to shots, and very few behavior changes. Overall, this studysupports the belief that the biopsy itself has little effect on a whale and that, if the associated vessel approach is conducted with care, samples can usually be taken with minimal disturbance to the target animal. However, approaches may affect the probability of obtaining fluke photographs for individual identification.

Clapham, P.J., D.K. Mattila and P.J. Palsbøll.
High-latitude composition of humpback whale competitive groups in Samana Bay: further evidence for panmixis in the North Atlantic population.
Canadian Journal of Zoology 71: 1065-1066.
Competitive groups of humpback whales, Megaptera novaeangliae, were observed in Samana Bay , Dominican Republic , West Indies . Photographs of ventral fluke patterns were used to identify individuals, and skin biopsies were taken for molecular determination of sex. Nine groups contained two or more whales previously identified from different high-latitude areas. In seven groups, males from different feeding grounds were observed to compete with each other, and in six cases the group's female was from a different area than at least one of her male escorts. These results provide further support for the hypothesis that the western North Atlantic population of this species can be considered a single panmictic unit.

Clapham, PJ, Baraff, LS, Carlson, CA, Christian, MA, Mattila, DK, Mayo, CA, Murphy, MA, Pittman,S.
Seasonal occurrence and annual return of humpback whales in the southern Gulf of Maine.
Canadian Journal of Zoology. 71:440-443.
A study of 518 individually identified humpback whales (Megaptera novaeangliae) in the southern Gulf of Maine between 1979 and 1988 showed high rates of both within-season occurrence and annual return. On average, 77.3% of whales were resighted on more than 1 day during the year (maximum 83 days), with occupancies ranging from 1 to 324 days (mean 88.1 days). The mean rateof return of individuals in consecutive years was 73.2 % (range 59.1 - 87.4 %), and the majority of whales were still being resighted up to 10 years later. Only 13 humpbacks were recorded during 50 midwinter surveys. Variation in the occurrence of individuals appears to be related to variability in the abundance of prey and perhaps to regional preferences.

Clapham, PJ.
Social organization of humpback whales on a North Atlantic feeding ground.
Symposia of the Zoological Society, London. 66:131-145.
Data from a long-term study of individually identified humpback whales, Megaptera novaeangliae, were used to describe patterns of association and grouping of this species on one of its principal North Atlantic feeding grounds in the southern Gulf of Maine. Most groups were small and unstable, and individual whales of both sexes and all age classes were associated with many conspecifics. Only six instances of stable associations were recorded. Analysis of the class composition of singles and pairs showed that: (1) among singles, juveniles of both sexes were significantly over-represented and mature females significantly under-represented; (2) male-female adult pairs were over-represented; (3) adult-juvenile pairs of any gender combination were under-represented; and (4) pairings between adult males were under-represented except during feeding. Only 12 of 2690 pairs consisted of animals that were known to be related. It is suggested that the fission-fusion sociality that characterized the study population represents a response to two ecological factors. Firstly, absence of predation nullifies the need for large groups for predator detection or communal defense. Secondly, the spatial characteristics of piscene prey favour a foraging strategy involving frequent changes in group size. In this system, kinship and dominance probably play reduced roles, while the apparent lack of territoriality is typical of taxa confronted by heterogeneously distributed and mobile resources. The apparent preference by mature males for associations with mature females may represent an attempt to establish bonds with potential future mates.

Schilling, MR, Seipt, IE, Weinrich, MT, Frohock, SE, Kulberg, AE, Clapham, PJ.
Behavior of individually-identified sei whales, Balaenoptera borealis, during an episodic influx into the southern Gulf of Maine in 1986.
Fishery Bulletin. 90:749-755.
Sei whales Balenoptera borealis are noted for major fluctuations in distribution, often in response to local availability of prey. An influx of sei whales occurred in the southern Gulf of Maine during summer 1986. Forty-seven individuals (including four mothers with calves) were photographically identified using natural markings, including dorsal-fin notches, placement of small circular scars on the animal's flank, and natural variation in dorsal-fin shape and pigment swaths along the dorsal surface behind the blowholes. Seventeen of these whales (36.1%) were photographed on more than one day, and the period between first and last sighting of individuals ranged from one to 66 days. Only six animals were sighted in more than one region in the southern Gulf of Maine. Observed behavior included traveling, nearsurface skim feeding, lunge feeding, and (rarely) “milling" or breaching. Group sizes were small and variable. Two individuals were matched to photographs taken in other regions in or near offshore Gulf of Maine waters. We hypothesize that the southern Gulf of Maine represents a short term feeding site. The occurrence of individuals without sufficient marks for individual recognition suggests that photoidentification is of limited value in the study of this species.

Hamilton, PK, Mayo,CA.
"Population characteristics of right whales, Eubalaena glacialis, observed in Cape Cod and Massachusetts Bays, 1978-1986"
Reports of the International Whaling Commission. (special issue 12):203-208.
Right whale, Eubalaena glacialis, occurrence in Cape Cod and Massachusetts Bays was investigated from 1978 through 1986. Using photo-identification techniques, a total of 113 individual whales were identified with a maximum of 47 whales sighted during a calendar year. Although whales were sighted in all months of the year except December, peak abundance occurred from February through April. Mothers with calves consistently appeared in April or later. The mean calving interval of nine mature females was three years. Residency in the study area varied from one to l65 days. An unusual summer residency group, including nine mother/calf pairs, present in the study area from July through October 1986, is discussed.

Mayo, CA, Marx, MK.
"Surface foraging behavior of the North Atlantic right whale, Eubalaena glacialis, and associated zooplankton characteristics"
Canadian Journal of Zoology. 68:2214-2220.
Right whales in Cape Cod Bay , Massachusetts , were studied to determine the relationship between their surface feeding behaviour and the density and composition of their planktonic prey. The swimming path characteristics of whales feeding, socializing and travelling were compared. Zooplankton samples collected in the feeding path were contrasted with those from areas where whales were not present. Surface prey patches where right whales fed were dominated by Calanus finmarchicus (21 samples), Pseudocalanus minutus (n = 13), Centropages sp. (n = 3), and larval barnacles (n = 2). The zooplankton density in the feeding path of the whales tested significantly higher (Mann-Whitney U-test, P < 0.001) than at stations where whales were not present (mean total densities were 6.54 x 103 (SE = 1.03 x 103) and O.87 x 103 (SE = 0. 19 x 103) organis MS/M3, respectively).Feeding was rarely observed in locations where the total zooplankton density was less than 1000 organisms/m3 The rate of change of direction in the feeding path (mean 19.3'/ 10 m of path) was significantly higher (P < 0.00 1) than for paths of whales travelling (mean 5.3'1 10 m of path), reflecting area-restricted foraging behaviour.