ACS Research Committee Report

DOLPHINS HOLD SECRETS TO BARNACLE-FREE BOATS
Source: UK Guardian

For years people have struggled to find an effective way to keep the underside of their boats clean without having to resort to using something so harsh that it would create a hazard to those creatures living in the water. Highly toxic paints help prevent the barnacles from forming, but clearly aren't the best solution.

Dolphins, being naturally streamlined, can cut through water at speeds of up to 30 mph, due to their natural ability to stay barnacle free. Biologists decided to figure out how they did it and see if anything could be created to mimic their formula for success.

A team of biologists and physicists studied members of the dolphin family such as the black pilot whale and took samples of their skin. The samples were then frozen at temperatures of -196 Celsius using liquid nitrogen and subsequently analyzed under scanning electron microscopes.

The dolphin's line of defense against unwanted companions is three-fold: first, the surface of their skin is not entirely smooth, but is slightly rippled every nanometer. This leaves hardly any protected niches where organisms can grow on their skin. Secondly, a gel-like substance that is rich in vitamins and enzymes covers their skin. This actively resists the mucus that various microorganisms often use to get their first foothold. Thirdly, the gel covering their skin contains enzymes that attack and destroy foreign bodies, causing them to fall away.

A synthetic resin with tiny particles to achieve a slightly uneven surface is planned. The hope is that this will duplicate the dolphin skin. They also plan to use some of the properties of the gel to repel organisms. They hope that this new method of protecting ships will become the benchmark for the industry.    

THERMOREGULATION IN GRAY WHALES

Gray whales (as well as other baleen whales) need to regulate their oral temperature while they feed in cold water. The tongue has no insulation and is highly vascularized, creating a potential for heat loss. Jim Heyning found that there are many countercurrent heat exchangers that converge at the base of the tongue and form a vascular bundle. In this way, warm blood coming from the body will heat the cold blood coming from the tongue. Temperature measurements seem to show that more heat can be lost through the blubber than through the tongue.    

2001 NORTH ATLANTIC RIGHT WHALE CONSORTIUM

The Right Whale Consortium is a group of North Atlantic right whale researchers. The Consortium meets once a year to discuss ongoing research projects and developments in conservation, such as shifting of shipping lanes and fishing gear modifications. The following summaries are only a select few of the presentations made during the two-day meeting.    

PASSIVE ACOUSTIC DETECTION AND TRACKING OF RIGHT WHALES IN CAPE COD BAY AND THE GREAT SOUTH CHANNEL: RESULTS AND IMPLICATIONS FOR FUTURE SURVEY EFFORTS.
Christopher Clark - Cornell Lab of Ornithology Bioacoustics Research Program

Bottom recorders were deployed in the Cape Cod Bay and the Great South Channel; they recorded thousands of right whale sounds at up to 200-300 calls per hour. The calls included contact calls (upsweeps- made up 80% of sounds), and surface activity (slaps, breaches), which ranges up to 3-5 nautical miles. Comparison of passive detection with aerial and boat-based surveys indicated that the recorders detected almost all of the whales seen from a survey, but many whales acoustically detected were not seen. This suggests that the acoustic recorders may present a more complete picture of the number/distribution of whales in these areas.    

THE NORTH ATLANTIC RIGHT WHALE CATALOGUE: AN UPDATE.
Philip Hamilton - New England Aquarium

The right whale catalogue, curated by the New England Aquarium, contains 410 identified individuals, of which 14 are known dead and only 301 have been seen alive in the last 6 years. The sex ratio of the population is approximately 50/50. In 2001, 31 calves were born, which is the highest number ever recorded. Four of these calves have been confirmed dead (two of ship strikes, two of unknown cause). In 2001, the average age of females when they first give birth was 14 years, which is 4 years older than the previously determined average. The average inter-birth interval was 6.2, a number that is again much higher than the previous average of 3.67 (early 1980's).    

SCARIFICATION ANALYSIS OF NORTH ATLANTIC RIGHT WHALES: MONITORING RATES OF ENTANGLEMENT INTERACTIONS.
Amy Knowlton

An analysis was conducted on the scarring on right whales, mostly on the tailstock, attributable to entanglement in fishing gear. It was found that 10-28% of the population acquires new entanglement scars annually. There is a higher rate of serious entanglement in juvenile animals. Since the 1980's, there have been 10 right whales, including "Churchill", seen in poor health with severe entanglements that were not resighted and are presumed dead. In addition, three rights (there has been a fourth since this report) have washed up with entanglement scars.    

CAN TAGGING RIGHT WHALES AID IN THEIR CONSERVATION AND RECOVERY?
Bruce Mate - Oregon State University Marine Mammal Program

In 2000, 16 right whales were equipped with satellite tags; nine of these individuals provided tracks for more than five days. The furthest movement was an adult female that traveled 1,928 km from the Bay of Fundy to Georgia, in 23 days. All tagged animals stayed in shallow (only up to 200m depth), coastal (less than 30km) waters for a significant amount of the study period. One of the tagged whales demonstrated typical movement patterns until suddenly its movement stopped while it was in Roseway Basin (off Nova Scotia) This sudden change in movement strongly indicates that the whale died, perhaps from a boat strike as it was in a high-use shipping area. In these circumstances, if satellite tracks are monitored real-time, researchers could recover carcasses that would otherwise be lost at sea and may be able to better evaluate human-related mortalities.    

ASSESSING SHIP STRIKE RISK FACTORS, AN UPDATE ON THE DTAG PROJECT.
Douglas Nowacek - Woods Hole Oceanographic Institution and Northeast Fisheries Science Center

Two playbacks, social sounds of right whales and sounds of an approaching vessel, were presented to tagged right whales. Changes in behavior, such as fluke stroke rate, heading and sound production, were measured versus the playback stimuli. There was little or no response to the vessel sound playback, but a definite response to playback of social sounds. In addition, analysis of the tagging data indicated that right whales use their buoyancy to return to the surface with little effort; the fluke stroke rate is significantly lower on ascent to the surface than on descent. There is a reduced ability to maneuver if the whales are not actively swimming. Therefore, the whales may be coming quickly to the surface and may be unable to move out of the way of approaching ships.   

14TH BIENNIAL CONFERENCE ON THE BIOLOGY OF MARINE MAMMALS

The Society for Marine Mammalogy holds a conference every other year. The 2001 conference, which took place November 28-December 3, was attended by over 1700 people, including researchers, educators and students. Many researchers from all over the world presented their work involving countless species, from pinnipeds, to dolphins, to large cetaceans. Due to the sheer volume of information, both talks and posters, the following are only a sample of those presentations that were attended and found very interesting by the research co-chairs: Kate Sardi and Allison Glass. There were many interesting presentations that are not included here and if anyone has any specific questions please contact us! Abstracts can be obtained from: pegasus.cc.ucf.edu/~smm/publications.htm.    

NEW SPECIES
The discovery of a new species was announced at the conference. A new beaked whale species was classified and named as Mesoplodon perrinii. It was named after Dr. Bill Perrin, who has worked in the field for many years and now works for the SW Fisheries Science Center, NMFS, in CA.    

REPRODUCTIVE SUCCESS OF FREE-RANGING BOTTLENOSE DOLPHINS: EXPERIENCE AND SIZE MAKE A DIFFERENCE.
Randy Wells - Chicago Zoological Society c/o Mote Marine Laboratory

Experienced (multiparous) mothers had a higher survival rate of calves than first-time mothers (primiparous). Multiparous females are generally larger and have a lower level of toxins in their bodies. Females rid their body of fat-soluble toxins during lactation; therefore, females that have had previous calves have already reduced their toxin load. Calves born into larger natal groups had a higher survival rate. Older males, seemingly regardless of size, had a higher rate of matings. There were also more matings for paired males; within each pair, either both or only one of the males may be the breeder.    

MATING PATTERNS AND INBREEDING AVOIDANCE IN NON-DISPERSING RESIDENT KILLER WHALES.
Barrett-Lennard - Vancouver Aquarium Marine Science Centre

An orca pod is defined as whales of the same matriline that spend over half of their time together. Several pods can be joined in "acoustic clans", which share some acoustic variants. Clans are thought to be created when pods divide; the whales no longer spend over half of their time together, but they share acoustics. Eventually, the acoustics of these clans will diverge. In both Alaska and British Columbia, orcas mate outside of their own pod and in British Columbia, they seem to show a preference to mating outside of their clan, as well. Between-clan matings usually occur between the most acoustically dissimilar pods.    

COMPARATIVE ANALYSIS OF BALEEN WHALE SONGS: PREDICTIONS FROM ACOUSTIC PROPAGATION AND IMPLICATIONS FOR MATING STRATEGIES.
Christopher Clark - Cornell Lab of Ornithology Bioacoustics Research Program

There are different acoustic constraints on coastal and pelagic species. Coastal species were defined as bowhead and right whales, pelagic as blue and fin whales and intermediate species as minke and humpback whales. The pelagic species produce consistently low frequency (10-30 Hz) songs lasting from 10-20 minutes. The blue whale's song can be recognized for up to 1600nm. There is a "notch" of low ambient noise in the environment between 10-100 Hz, which is exactly where fin and blue whale songs fall. In shallow water, the most efficient frequencies would be between 100Hz to 1KHz; the higher and lower extremes would be "stripped". The humpback, right and bowhead whales produce songs that fall within these frequency parameters, usually between 100-400 Hz. Increased sampling of mysticete song indicates that it occurs throughout the year and in a larger portion of the range than previously discovered; song is sometimes associated with areas of high prey density.    

MEGAPTERAN DIASPORA: MOVEMENT RATES OF HUMPBACK WHALES BETWEEN TWO FEEDING AGGREGATIONS ARE RELATED TO PREY AVAILABILITY.
Peter Stevick - Sea Mammal Research Unit, Gatty Marine Laboratory, University of St. Andrews

Between 1978 and the present, there was little to no observed movement of humpback whales between the US (Gulf of Maine) and Canada (Bay of Fundy/Newfoundland), except during one time period. Between 1984 and 1989 there was high level of movement between the two areas. There was a very low abundance of sand lance in the Gulf of Maine between 1982 and 1987, which probably indicates a two-year time lag between sand lance and whale movement. Sand lance were also low in the early 1990's and there was little humpback movement; however, during this time, there was an increase in herring abundance. There is probably a threshold in the "forage fish " (includes both herring and sand lance) that correlates to whale movements.    

DO MINKE WHALES SING? ANALYSIS OF DISCRETE CATEGORIES IN A REPETITIVE BREEDING SEASON SOUND SEQUENCE.
Jason Gedamke - Department of Ocean Sciences, University of California at Santa Cruz

There were three categories of minke whale sounds: frequency-modulated upsweeps, "social sounds", which includes a wide continuum of amplitude and frequency-modulated sounds, and song. Three types of song were identified: rapid song, 30s song and 200s song. The rapid song was produced at a lower source level and the song sequences were shortened, indicating that this may be an intermediate between song and social sounds and may be used for a different function than the other two types of song. Only the 30s and 200s song were used in these analyses and the sex of the singers was unknown. There was an average of 2.5km between singers and singers were never less than 1.4km from one another. Song is most likely used, in part, as a spacing mechanism between minkes.    

ACOUSTIC VOCALIZATIONS AND MOVEMENT PATTERNS OF A TAGGED SPERM WHALE (PHYSETER MACROCEPHALUS) DURING FORAGING DIVES.
Mark Johnson - Woods Hole Oceanographic Institution

The tag records depth, sound, and the speed, pitch and roll movement of the tagged animal. The sounds produced by the sperm whales seems to follow a pattern of regular echolocation clicks, followed by a creak (clicks at a much higher rate), then a pause and a resumption of regular clicks. Sperm whales are upside down significantly more often on the descent of dive and right side up on the ascent of dive. Creaks and an increase in speed oftentimes coincided with roll events. The inter-click interval and dive profile are closely related; as the sperm whale is deeper in the water, the inter-click interval is shorter (click rate is higher). One hypothesis is that the whale is using these clicks to detect the bottom. When the whale is deeper in the water, the distance to the bottom is less, the clicks echo back to the whale sooner, leading to the higher click rate.    

NORTH ATLANTIC RIGHT WHALE CALVING SUCCESS: LINKAGES TO THE NORTH ATLANTIC OSCILLATION, OCEANOGRAPHIC PATTERNS, AND PREY AVAILABILITY.
Robert Kenney - University of Rhode Island, Graduate School of Oceanography

In contrast to previous studies, there was no significant correlation found between the North Atlantic oscillation (NAO) and number of right whale calves between the years 1982 and 2001. However, when right whales were divided into "Fundy" calves and "Non-Fundy" calves, the correlation between the NAO and non-fundy calves was significant in all years. One to two years after a switch from a positive to a negative NAO, there is a shift in the northwest Atlantic from warm, high salinity water to colder, lower salinity water from the Labrador Subarctic Current. This shift coincides with a decline in right whales' principle plankton prey species, Calanus finmarchicus. Right whale births are correlated with the abundance of Calanus and, in turn, the shift in the NAO .    

ATLANTIC WHITE-SIDED DOLPHIN SOCIAL STRUCTURE BASED ON STRANDING TRENDS AND GENETICS.
Kim Amaral - Biology Department Woods Hole Oceanographic Institution/ UMass Dartmouth

Three subpopulations of Atlantic white-sided dolphins: Gulf of Maine, Gulf of St. Lawrence, and Labrador Sea. In the 1970's, there was a change in distribution from the continental slope to the shelf and it is now the most common species to strand. There were more strandings in the winter, when the dolphins migrate inshore. There was a sexual skew towards either males or females in mass strandings, meaning that males and females segregate in the population. Genetic studies showed some inbreeding to be present in the population, but that males usually mate outside of their natal groups.    

PACIFIC KILLER WHALES (ORCINUS ORCA): SENTINELS OF A CONTAMINATED PLANET.
Presenter: Peter Ross - Fisheries and Oceans Canada, Institute of Ocean Sciences

Southern resident orcas (typically found from mid-coast Washington state to the southern tip of Vancouver Island) have gone through a 20% decline in the last 5 years, leaving a population of only 78 individuals. PCBs were banned in 1975, but populations of orcas still have high levels in their bodies; the highest levels of these toxins are found in the transient and southern resident orcas. PCBs are known to cause problems in reproduction, immune system, growth and development, and neurology. The contaminant load in males is much higher than females, which pass these toxins to their offspring through their milk. The PCB levels in these orcas range from 150 to 240 ppm, which is 2-3 times higher than the belugas of the Gulf of St. Lawrence. Fish were tested before and after their migration from the west coast of North America. When they left the area as smolts, the average amount of contaminant in their bodies was 1ug, but when they returned as full-grown salmon, the average was 189ug. These toxins are getting into the local environment from somewhere offshore. These toxins are a global problem; it is estimated that it would take only 5-7 days for PCBs released in China to reach the coast of North America.