Vessel Strikes Research Articles

Assessment of management to mitigate anthropogenic effects on large whales.

United States and Canadian governments have responded to legal requirements to reduce human-induced whale mortality via vessel strikes and entanglement in fishing gear by implementing a suite of regulatory actions. We analyzed the spatial and temporal patterns of mortality of large whales in the Northwest Atlantic (23.5°N to 48.0°N), 1970 through 2009, in the context of management changes. We used a multinomial logistic model fitted by maximum likelihood to detect trends in cause-specific mortalities with time. We compared the number of human-caused mortalities with U.S. federally established levels of potential biological removal (i.e., species-specific sustainable human-caused mortality). From 1970 through 2009, 1762 mortalities (all known) and serious injuries (likely fatal) involved 8 species of large whales. We determined cause of death for 43% of all mortalities; of those, 67% (502) resulted from human interactions. Entanglement in fishing gear was the primary cause of death across all species (n = 323), followed by natural causes (n = 248) and vessel strikes (n = 171). Established sustainable levels of mortality were consistently exceeded in 2 species by up to 650%. Probabilities of entanglement and vessel-strike mortality increased significantly from 1990 through 2009. There was no significant change in the local intensity of all or vessel-strike mortalities before and after 2003, the year after which numerous mitigation efforts were enacted. So far, regulatory efforts have not reduced the lethal effects of human activities to large whales on a population-range basis, although we do not exclude the possibility of success of targeted measures for specific local habitats that were not within the resolution of our analyses. It is unclear how shortfalls in management design or compliance relate to our findings. Analyses such as the one we conducted are crucial in critically evaluating wildlife-management decisions. The results of these analyses can provide managers with direction for modifying regulated measures and can be applied globally to mortality-driven conservation issues.Evaluación del Manejo para Mitigar Efectos Antropogénicos sobre Ballenas MayoresResumenLos gobiernos de Estados Unidos y Canadá han respondido a requerimientos legales para reducir la mortalidad de ballenas inducida por humanos por medio de impacto con embarcaciones y enmarañamiento en artes de pesca mediante la implementación de un conjunto de acciones reguladoras. Analizamos los patrones espaciales y temporales de la mortalidad de ballenas mayores en el Atlántico Noroccidental (23.5°N a 48.0°N), de 1970 a 2009, en el contexto de cambios de manejo. Utilizamos un modelo logístico multinomial ajustado por la máxima probabilidad de detección de tendencias en mortalidades por causa específica en el tiempo. Comparamos el número de muertes provocadas por humanos con los niveles de remoción biológica potencial (i.e., mortalidad específica provocada por humanos sustentable). De 1970 a 2009, hubo 1762 muertes (conocidas) y lesiones serias (casi fatales) involucrando 8 especies de ballenas mayores. Determinamos la causa de 43% de todas las muertes; de ellas, 67% (502) resultaron de interacciones humanas. El enmarañamiento en artes de pesca fue la causa principal de muerte en todas las especies (n = 323), seguida de causas naturales (n = 248) e impacto de embarcaciones (n = 171). Los niveles sustentables de mortalidad establecidos fueron excedidos consistentemente hasta en 650% en 2 especies. Las probabilidades de muerte por enmarañamiento y por impacto de embarcaciones incrementaron significativamente de 1990 a 2009. No hubo cambio significativo en la intensidad local de mortalidad por todas las causas o por impacto de embarcaciones antes y después de 2003, año en el que se implementaron numerosos esfuerzos de mitigación. Hasta ahora, los esfuerzos regulatorios no han reducido los efectos letales de las actividades humanas sobre las ballenas a nivel de población, aunque no excluimos la posibilidad de éxito de medidas enfocadas a hábitats locales específicos que no estuvieron dentro de la resolución de nuestro análisis. No es claro como se relacionan con nuestros resultados las deficiencias en el diseño o implementación del manejo. Análisis como el que realizamos son cruciales para la evaluación crítica de decisiones para el manejo de vida silvestre, y los resultados de estos análisis pueden proporcionar directrices a los manejadores para que modifiquen medidas regulatorias y puedan ser aplicadas globalmente en temas de conservación relacionadas con mortalidad.

Age and Growth of Atlantic Sturgeon in the James River, Virginia, 1997–2011

AbstractHistorically the Chesapeake Bay supported a large population of Atlantic sturgeonAcipenser oxyrinchus, but loss of suitable spawning habitat and overfishing coincided with dramatic in‐system declines throughout the 20th century. Atlantic sturgeon harvest moratoriums were implemented in 1974 for Virginia waters and were expanded coastwide in 1998. In 1997, researchers became aware that commercial fishers in the James River, a tributary of the Chesapeake Bay, were catching juvenile and subadult Atlantic sturgeon as bycatch in various fisheries. Genetic studies showed that the Chesapeake Bay population has maintained genetic integrity and qualifies as a distinct population segment. Between 2007 and 2011, almost 150 adults have been caught in the tidal–freshwater portion of the James River during putative spawning runs. Pectoral fin spines from juveniles and subadults collected in the Burwell Bay (rkm 40) and Cobham Bay (rkm 60) areas and mature adult samples from vessel strikes in freshwater around or above rkm 120 were analyzed to create a length‐at‐age curve for Atlantic sturgeon in the James River. Five models were used to analyze the data, and the double von Bertalanffy (k1= 0.054,k2= 0.097,t1= −2.85,t2= 1.09,tp= 6.03 years,L∞= 2241 mm) provided the best fit to the observed data. We estimated an increase in growth coefficient attp, which could be an artifact of low sample size or due to ontogenetic changes in habitat use as older fish spend more time in oceanic waters than younger fish. Atlantic sturgeon in the 6–9 year age range are rarely encountered in the James River compared with younger and older age‐classes, so a more in‐depth analysis of the increased growth coefficient would require ocean sampling.

Summary of Reported Whale-Vessel Collisions in Alaskan Waters

Here we summarize 108 reported whale-vessel collisions in Alaska from 1978–2011, of which 25 are known to have resulted in the whale's death. We found 89 definite and 19 possible/probable strikes based on standard criteria we created for this study. Most strikes involved humpback whales (86%) with six other species documented. Small vessel strikes were most common (<15 m, 60%), but medium (15–79 m, 27%) and large (≥80 m, 13%) vessels also struck whales. Among the 25 mortalities, vessel length was known in seven cases (190–294 m) and vessel speed was known in three cases (12–19 kn). In 36 cases, human injury or property damage resulted from the collision, and at least 15 people were thrown into the water. In 15 cases humpback whales struck anchored or drifting vessels, suggesting the whales did not detect the vessels. Documenting collisions in Alaska will remain challenging due to remoteness and resource limitations. For a better understanding of the factors contributing to lethal collisions, we recommend (1) systematic documentation of collisions, including vessel size and speed; (2) greater efforts to necropsy stranded whales; (3) using experienced teams focused on determining cause of death; (4) using standard criteria for validating collision reports, such as those presented in this paper.

Implications of Arctic industrial growth and strategies to mitigate future vessel and fishing gear impacts on bowhead whales

Abstract The objective of this paper was to investigate and illustrate how insights gained from experience managing human activities in order to protect North Atlantic right whales (Eubalaena glacialis) along the heavily industrialized east coast of North America might be applied in the Arctic, where bowhead whales (Balaena mysticetus) face some of the same risks as right whales. The reduced extent and thickness of sea ice and the resultant longer open-water season have major, complex implications for the Arctic marine ecosystem. Increased maritime ship traffic and commercial fishing in the Arctic are bound to affect bowheads and Native (indigenous) hunting communities who depend on whales for subsistence and cultural identity. Bowheads and right whales were greatly depleted by commercial whaling in the 19th and early 20th centuries. While the Western Arctic bowhead population has been recovering steadily in recent decades, North Atlantic right whales remain highly endangered because of persistent lethal and sublethal vessel strikes and frequent entanglement in commercial fishing gear. Entanglement can be transitory or persistent, with debilitation lasting for months before the animal finally succumbs. Vessel strike and fishing gear trauma has been documented in bowheads, but at a much lower rate than in right whales. Initiatives intended to mitigate the impacts of ship traffic on North Atlantic right whales have included speed limits and routing changes. Those meant to reduce the incidence and severity of entanglements include the modification of gear design and gear deployment practices. Management measures need to be considered in advance in the Arctic in order to minimize the risks to bowhead whales as shipping and industrial fishing expand in the Arctic with ice retreat.

Dangerous dining: surface foraging of North Atlantic right whales increases risk of vessel collisions

North Atlantic right whales are critically endangered and, despite international protection from whaling, significant numbers die from collisions with ships. Large groups of right whales migrate to the coastal waters of New England during the late winter and early spring to feed in an area with large numbers of vessels. North Atlantic right whales have the largest per capita record of vessel strikes of any large whale population in the world. Right whale feeding behaviour in Cape Cod Bay (CCB) probably contributes to risk of collisions with ships. In this study, feeding right whales tagged with archival suction cup tags spent the majority of their time just below the water's surface where they cannot be seen but are shallow enough to be vulnerable to ship strike. Habitat surveys show that large patches of right whale prey are common in the upper 5 m of the water column in CCB during spring. These results indicate that the typical spring-time foraging ecology of right whales may contribute to their high level of mortality from vessel collisions. The results of this study suggest that remote acoustic detection of prey aggregations may be a useful supplement to the management and conservation of right whales.

Response by vessel operators to protection measures for right whales Eubalaena glacialis in the southeast US calving ground

Vessel strikes are the leading cause of mortality for the endangered North Atlantic right whale Eubalaena glacialis. Prior to a December 2008 implementation of a mandatory, seasonally based vessel-speed rule (10 knots, 18.5 km h–1) along the eastern US seaboard, voluntary recommended speeds and routes were established. We used Automatic Identification System (AIS) data to evaluate and compare the compliance rates between the mandatory and voluntary measures to protect right whales in the southeast US critical habitat area off Florida and Georgia during the winters from 2005–06 to 2008–09. Vessel compliance was significantly higher under mandatory versus voluntary recommended speed restrictions, with compliance rates of 75 and 16%, respectively. Average vessel speeds were slower under mandatory speed restrictions (10.5 knots, 19.6 km h–1) compared to voluntary recommended speed restrictions (14.5 knots, 26.9 km h–1). Although vessels only slow down when mandated, they change their routing voluntarily. Compliance rates with voluntary recommended routes steadily increased during this period, from 43% prior to rulemaking, to 52% during the first year, 84% in the second year, and 96% in the final year of the study. Combining reduced speeds with recommended routes reduces the probability of right whale mortality from ships by 71.9% from the pre-implementation period. These results support long-term implementation of both vessel-speed reduction and restricted vessel routes for the survival and recovery of the North Atlantic right whale.

Atlantic Sturgeon Vessel‐Strike Mortalities in the Delaware Estuary

AbstractThe Atlantic Sturgeon Status Review Team has recommended that the Secretary of Commerce list the New York Bight distinct population segment of Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus), which includes the Delaware River and Hudson River populations, as threatened under the federal Endangered Species Act. Between 2005 and 2008, a total of 28 Atlantic sturgeon mortalities were reported in the Delaware Estuary. Sixty‐one percent of the mortalities reported were of adult size and 50% of the mortalities resulted from apparent vessel strikes. The remainder of the mortalities were too decomposed to ascertain the cause of death, but the majority were likely the result of vessel strikes. For small remnant populations of Atlantic sturgeon, such as that in the Delaware River, the loss of just a few individuals per year due to anthropogenic sources of mortality, such as vessel strikes, may continue to hamper restoration efforts. An‐egg‐per‐recruit analysis demonstrated that vessel‐strike mortalities could be detrimental to the population if more than 2.5% of the female sturgeon are killed annually. We report on our observations of vessel‐strike mortalities in the Delaware Estuary, discuss the possible implications for the Delaware River population, and recommend further research.

Cetaceans and the petroleum industry—coexistence or mutual exclusion?

Legends, myths and plain old misinformation abound of whale migrations interrupted by international shipping, dolphin populations displaced by dredging activities, and of seismic survey campaigns resulting in disoriented, beached whales. While risks exist, in truth the Australian petroleum industry continues to demonstrate that it can successfully coexist productively alongside populations of cetacean. These whales and dolphins are seemingly able to at least tolerate, if not actually be undisturbed by, underwater noise. Other risks to cetaceans from oil and gas activities, whether actual or perceived, encompass vessel strike, turbidity plumes from dredging, port developments, underwater blasting, spills, the laying and operation of pipelines, and similar. URS Australia’s John Polglaze is a specialist in the environmental impact evaluation of underwater noise, and has over 15 years experience in marine environmental management and impact assessment following nearly 20 years service in the Royal Australian Navy. John presents on the range of environmental impact assessment challenges for the oil and gas industry in Australian coastal and offshore regions, and effective, pragmatic solutions for demonstrating low risks to cetaceans and other sensitive marine fauna. These include the application and limitations of computer-based models to predict underwater noise and blast propagation, the development of a risk assessment framework that has proven effective with state and Commonwealth regulators, and case studies of real-life interactions between the petroleum industry and cetacean populations. In particular, he will discuss how misunderstanding and misapprehension of these complex issues unnecessarily complicates the challenges of environmental compliance. This topic is timely, given that Australia’s rapidly increasing whale populations, coupled with the continued expansion of offshore petroleum activities, will lead to more frequent interaction between and overlap of cetaceans and oil and gas activities.

Efficacy of a Voluntary Area to Be Avoided to Reduce Risk of Lethal Vessel Strikes to Endangered Whales

Ocean-going vessels pose a threat to large whales worldwide and are responsible for the majority of reported deaths diagnosed among endangered North Atlantic right whales (Eubalaena glacialis). Various conservation policies have been implemented to reduce vessel-strike mortality in this species. The International Maritime Organization adopted the Roseway Basin Area to be avoided on the Scotian Shelf as a voluntary conservation initiative to reduce the risk of lethal vessel strikes to right whales. We initiated the Vessel Avoidance & Conservation Area Transit Experiment to evaluate the efficacy of this initiative because the effectiveness of the avoidance scheme in reducing risk without the imposition of vessel-speed restrictions depends entirely on vessel-operator compliance. Using a network of automatic identification system receivers, we collected static, dynamic, and voyage-related vessel data in near real time from the Roseway Basin region for 12 months before and 6 months after the implementation of the area to be avoided. Using pre- and post-implementation vessel navigation and speed data, along with right whale sightings per unit effort data, all resolved at 3'N latitude by 3'W longitude, we estimated the post-implementation change in risk of lethal vessel strikes. Estimates of vessel-operator voluntary compliance ranged from 57% to 87% and stabilized at 71% within the first 5 months of implementation. Our estimates showed an 82% reduction in the risk of lethal vessel strikes to right whales due to vessel-operator compliance. We conclude that the high level of compliance achieved with this voluntary conservation initiative occurred because the area to be avoided was adopted by the International Maritime Organization. Our results demonstrate that international shipping interests are able and willing to voluntarily alter course to protect endangered whales.

Probability and mitigation of vessel encounters with North Atlantic right whales

Successful mitigation of vessel-whale encounters requires quantitative estimates of vessel strikes, how strike rates change over time, where strikes are most likely to occur, and options for minimizing strikes. In addressing these issues, we first demonstrate a 3- to 4-fold increase in the number of reported large whale-vessel strikes worldwide from the early 1970s to the early 2000s, corresponding to a 3-fold increase in the number of vessels in the world fleet that is paralleled by an increase in vessel tonnage and speed. Second, we estimate a 50% chance of 14 or more annual ves- sel-strike reports worldwide between 1999 and 2002. For North Atlantic right whales Eubalaena glacialis, we estimate a 60% chance of observing at least 1 right whale death from vessel strike. Adjusting for undetermined causes of death and unobserved deaths, we estimate a 10-fold increase (from 1 to 10) in the expected annual number of fatal ship strikes. Third, we evaluate the eastern United States geographic distribution of right whales and vessels to calculate relative probabilities of vessel-whale encounters among 3 major right whale habitats. We determine that the Southern Calv- ing Ground poses the greatest threat of a vessel strike: 1.6- and 7-fold greater than in Cape Cod Bay and the Great South Channel, respectively. Finally, for the Great South Channel region we present a quantitatively determined vessel-traffic routing option that would achieve a 39% reduction in ves- sel-whale encounter probabilities. The methods employed in assessing encounter probabilities and vessel-routing options can be applied elsewhere to enhance the conservation of endangered and threatened species that suffer vessel-strike mortality.

Abundance and conservation status of the Yangtze finless porpoise in the Yangtze River, China

The Yangtze finless porpoise ( Neophocaena phocaenoides asiaeorientalis) is endemic to the middle and lower reaches of the Yangtze River, China. It is the only freshwater population of porpoises in the world and is currently listed as Endangered by IUCN. In November and December 2006 we used two boats and line transect methods to survey the entire current range of the population, except for two lakes (Poyang and Dongting). Sighting results were similar for both boats, so we pooled all data and analyzed them using two line transect models and a strip transect model. All models produced similar estimates of abundance (1111, 1225 and 1000). We then added independent estimates of the number of porpoises from the two lakes for a total estimate of approximately 1800 porpoises. Our findings indicate that the population continues to decline and that its distribution is becoming more fragmented. Our current estimate in the main river is slightly less than half the estimate from surveys between 1984 and 1991 (which was probably an underestimate). We also found an apparent gap in the distribution of porpoises between Yueyang and Shishou (∼150 km), where sightings had previously been common. Continued threats to Yangtze finless porpoises include bycatch in unregulated and unselective fishing, habitat degradation through dredging, pollution and noise, vessel strikes and water development. Immediate protective measures are urgently needed to ensure the persistence of finless porpoises in the Yangtze River. The survey design and analytical methods developed in this study might be appropriate for surveys of cetaceans in other river systems.

Consequences of injuries on survival and reproduction of common bottlenose dolphins (Tursiops truncatus) along the west coast of Florida

AbstractAccurate identification of human‐induced injuries that lead to death or interfere with reproduction is important for marine mammal management, as deaths exceeding established limits can lead to restrictions on fisheries or vessel operations. The fates of cetaceans last seen swimming with attached gear, particularly in pelagic fisheries, or with vessel strike lacerations, have been difficult to predict. Survival and reproduction data from long‐term research on resident common bottlenose dolphins near Sarasota, Florida were examined relative to consequences of fishing gear ingestion, line entanglements, vessel strikes, and amputations of unknown origins. Fishing hooks embedded in the throat, goosebeak, or esophagus, or line wrapped around the goosebeak, generally lead to death. Multiple, constrictive line wraps around fin insertions can lead to amputation, blood loss, impaired mobility, or infection. Dolphins with ingested gear or severe entanglements may swim away with the gear, but likely die later. Propeller injuries involving only soft tissue were often survivable. Some dolphins survived amputations of the distal ends of fins, and continued to reproduce. As a precautionary approach, dolphins with ingested gear or severe constrictive entanglements should be considered mortalities, but extrapolations of findings from coastal bottlenose dolphins to other cetaceans and different gear must be done with caution.

Statistical modeling of North Atlantic right whale migration along the mid-Atlantic region of the eastern seaboard of the United States

North Atlantic right whale feeding and calving behaviors provide predictable spatial and temporal windows in which to conduct surveys and facilitate collection of opportunistic sightings data. Migration behavior makes it more difficult to locate and sample marine animals systematically or to observe them opportunistically. The lack of data creates a critical gap in understanding social behavior; it also hampers the development of mitigation strategies to anthropogenic disturbances such as vessel strikes, acoustic pollution and entanglements. We employ regression analysis to fill this gap to model northerly movements of North Atlantic right whales in the coastal mid-Atlantic migratory corridor of the United States. The modeling suggests an early to mid-March departure from Jacksonville, Florida, with a 30 day departure range; an average travel time of 21–24 days to the tip of Long Island, corresponding to a mean migration/displacement rate of 1.5–1.7 knots (2.8–3.1 km/h). Right whales migrating with calves begin their northern migration several days after right whales migrating without calves. These statistical models can supplement the absence of migratory survey data and help direct and stratify survey efforts in migratory corridors. The combination of rigorous statistical prediction with direct observation also should facilitate the creation of more effective mitigation measures. The methods employed here can be applied to other megafauna elsewhere around the world in many situations where migratory data are sparse.

Vessel collisions with small cetaceans worldwide and with large whales in the Southern Hemisphere, an initial assessment

Collisions with vessels are a well-documented conservation problem for some populations of large whales (LW) in the Northern Hemisphere. Less attention has been given to incidents in the Southern Hemisphere or to small cetaceans (SC) worldwide, therefore an experimental database was compiled (N=256; 119 LW, 137 SC) to allow a rapid assessment. Confirmed collision records were identified for 25 species (7 LW, 18 SC) and unconfirmed but probable records for 10 other species (2 LW, 8 SC). Among LW, ship-caused mortality and traumatic injuries seem to affect primarily southern right (56 reported cases), humpback (15) and Bryde's whales (13), but also sperm (8), blue (5), sei (4) and fin whales (2) are involved, and probably Antarctic minke and dwarf minke whales. Southern right whale populations off South Africa and off eastern South America (Brazil, Uruguay and Argentina) suffer significant mortality. Incidence and potential population impact vary widely among the 26 small cetacean species for which collision records exist. Vessel strikes in at least two populations each of the Indo-Pacific humpback dolphin (Xiamen and Hong Kong/Pearl River, possibly western Taiwan), Irrawaddy dolphin (Mahakam River, Chilika Lagoon, possibly Laos) and finless porpoise (Yangtze River, Hong Kong) may directly compromise long-term survival. Annual vessel-caused mortality (min. 2.9% of population) for Irrawaddy dolphins in the Mahakam River may not be sustainable. The quasi-extinction of the baiji warns for a potential similar fate for the Yangtze River finless porpoise and Ganges river dolphin. Two calves of the endangered Hector's dolphin are known killed by boats. All highly impacted species have a neritic, estuarine or fluviatile habitat, areas where vessel traffic is concentrated. Species that may receive a moderate impact from collisions but which may be sustainable at species level (because many strikes are nonlethal), include common bottlenose dolphins, killer whales, short-finned pilot whales and pygmy sperm whales. Almost 2% of common bottlenose dolphins in the Gulf of Guayaquil showed propeller-inflicted injuries and scars. Propeller guards should be made compulsory for all boat-based cetacean tourism, as habituation to boat traffic seems a contributing factor in accidents. Low impact occurs in 15 small cetacean species with only few reported vessel strikes. However, vast underreporting is thought to be the norm and there is a need for a global, standardised database.

VESSEL COLLISIONS WITH WHALES: THE PROBABILITY OF LETHAL INJURY BASED ON VESSEL SPEED

AbstractHistorical records demonstrate that the most numerous, per capita, ocean‐going‐vessel strikes recorded among large‐whale species accrue to the North Atlantic right whale (Eubalaena glacialis). As vessel speed restrictions are being considered to reduce the likelihood and severity of vessel collisions with right whales, we present an analysis of the published historical records of vessels striking large whales. We examine the influence of vessel speed in contributing to either a lethal injury (defined as killed or severely injured) or a nonlethal injury (defined as minor or no apparent injury) to a large whale when struck. A logistic regression model fitted to the observations, and consistent with a bootstrap model, demonstrates that the greatest rate of change in the probability of a lethal injury (Plethal) to a large whale occurs between vessel speeds of 8.6 and 15 knots where Plethal increases from 0.21 to 0.79. The probability of a lethal injury drops below 0.5 at 11.8 knots. Above 15 knots, Plethal asymptotically approaches 1. The uncertainties in the logistic regression estimates are relatively large at relatively low speeds (e.g., at 8 knots the probability is 0.17 with a 95% CI of 0.03–0.6). The results we provide can be used to assess the utility of vessel speed limits that are being considered to reduce the lethality of vessels striking the critically endangered North Atlantic right whale and other large whales that are frequent victims of vessel strikes.

Vessel-related mortality of sea turtles in Queensland, Australia

Identification of threats is a standard component of conservation planning and the ability to rank threats may improve the allocation of scarce resources in threat-mitigation programs. For vulnerable and endangered sea turtles in Australia, vessel strike is recognised as an important threat but its severity relative to other threats remains speculative. Documented evidence for this problem is available only in stranding records collected by the Queensland Environment Protection Authority. With the authority’s support we assessed the scope and quality of the data and analysed vessel-related records. We found adequate evidence that during the period 1999–2002 at least 65 turtles were killed annually as a result of collisions with vessels on the Queensland east coast. This level of mortality appears broadly comparable to that recorded in the Queensland East Coast Trawl Fishery before the introduction of mandatory turtle-exclusion devices in that fishery. Green turtles (Chelonia mydas) comprised the majority of vessel-related records, followed by loggerhead turtles (Caretta caretta), and 72% of cases concerned adult or subadult turtles. The majority of vessel-related records came from the greater Moreton Bay area, followed by Hervey Bay and Cleveland Bay. The waters of all three areas are subject to variable levels of commercial and recreational vessel traffic, and their shores are both populated and unpopulated.

Southern Right Whale Eubalaena australis sightings on the Australian coast and the increasing potential for entanglement

Southern Right Whales Eubalaena australis are an endangered species that have been recovering from unsustainable whaling practices and, despite being reported along the east and west coasts of Australia, they have not been duly accounted for in recent risk assessments for marine development. This review of the last decade of sightings highlights northerly movements into temperate and sub-tropical waters, indicates that fatal entanglement has occurred and points toward an increasing likelihood of interactions between migrating whales and inshore marine development. Given that entanglements and vessel strike are preventing the recovery of North Atlantic Right Whales Eubalaena glacialis, we recommend a precautionary approach to risk assessment around Australia and the formation of a national animal entanglement committee with both a pre-emptive role in assessing coastal development applications and a reactive role in the event of entanglement.

Dissemination of Northern Right Whale (Eubalaena glacialis) Sighting Information to the Southeast U.S. Maritime Community

Northern right whales (Eubalaena glacialis) are vulnerable to injury and mortality caused by vessel strikes. In an effort to prevent vessel strikes in the southeastern U.S. calving ground, a communication network was implemented to relay right whale sighting information, gathered by aerial survey teams, to mariners in the area. The system, which has evolved substantially since inception, now provides real-time sighting information to the marine community, thus assisting with avoidance of northern right whales. The current system utilizes 25 cloned alphanumeric pagers distributed to various state, federal, military, and industry representatives. Right whale sightings are reported and disseminated via the pagers, and ultimately via Navigational Telex (NAVTEX) to all ships 100 tons or larger in southeastern waters. This system has been successful in alerting mariners to the presence of right whales, however to address the critical management problems confronting this highly endangered species, further research into technological advancements that may assist in the detection of right whales should be encouraged.

The marine mammals of the Gulf of Mexico

Recorded knowledge of marine mammals of the Gulf began with commercial whaling of sperm whales, short-finned pilot whales, and Risso’s dolphins in the 1700s and 1800s, progressed to natural history observations and one of the first volunteer stranding organizations, the Texas Marine Mammal Stranding Network, in the 1970s. The vegetarian sirenian, the West Indian manatee (Trichechus manatus), occurs mainly in Florida. All others are cetaceans, members of the whale and dolphin clades. There are no porpoises, sea lions, fur seals, or true seals in the Gulf. The most common cetacean in the Gulf numerically is the pantropical spotted dolphin (Stenella attenuata), and the one with most biomass is the sperm whale (Physeter macrocephalus), common in mid-depth waters off Louisiana and the shelf break off Texas. Major anthropogenic threats exist for all marine mammals but do not appear to be as intensive in the Gulf as in several other oceanic basins. Threats to marine mammals in the Gulf include prey depletion, incidental mortality, injury due to fisheries, intentional and direct takes, vessel strikes, disturbance, acoustic (noise) pollution, chemical contamination, ingestion of solid debris, oil spills, and aspects of ecosystem change.