Ward, N.

Accurate species identification of marine mammals is key to improving our knowledge about them, including their distribution, natural history and the causes of their deaths. Marine mammals face many human-related challenges. Entanglement in active and discarded fishing gear poses a serious threat. Where their ranges overlap with human activities, marine mammals may also suffer from disturbance, vessel collision and exposure to contaminants, as well as loss of feeding, mating and nursery habitats. An impediment to marine mammal conservation is the scarcity of knowledge about their normal habitat, diet, behavior and demographics, and how human impacts affect these critical factors. Our principal hope is that this field guide will assist in correctly identifying stranded marine mammals, and that associated research will lead to an increased understanding of their lives, both for the sake of ‘filling the gaps’ of our knowledge and to design better conservation measures to protect them in the Wider Caribbean Region (WCR).

A stranded marine mammal is defined as a marine mammal found dead on the beach or one that is alive but in a helpless position; for example, one that comes ashore ill, weak or simply lost. Every year thousands of whales and dolphins are found stranded alive or dead on beaches all over the world. They may be alone or in groups. Some animals are old or unwell, but many of them are young and otherwise in good health. This is a natural phenomenon that has been recorded for centuries. The mechanisms behind such events, however, remain one of the great mysteries of the animal kingdom.

Single strandings are generally considered the result of normal mortality, disease processes or associated with human actions. Regardless of whether they strand alive or dead, single-stranded animals soon die. The expression mass-stranded generally refers to a simultaneous stranding of two or more cetaceans of the same species, other than a female and her calf. Mass strandings are harder to understand. They occur when a group of toothed whales come ashore alive. Such animals rapidly encounter serious problems with sunburn, dehydration and other aspects of exposure. Some mass strandings (i.e., beaked whales) exhibit a broader distribution in time and space than typical mass strandings, which are generally confined to a specific area.

This guide is produced by ECCN:

The Eastern Caribbean Cetacean Network (ECCN) is a regional volunteer organization that tracks sightings and strandings of whales and dolphins in the Eastern Caribbean (the Lesser Antilles). Through research and education, ECCN’s mission is to gain community support for the protection of resident and migratory whales and dolphins and their critical marine habitats. ECCN has been a primary contributor in the inception and development of the Action Plan for the Conservation of Marine Mammals (MMAP) of the Wider Caribbean Region (WCR) under the auspices of the United Nations Environment Programme’s (UNEP) Protocol for Specially Protected Areas and Wildlife (SPAW). Since 2005, ECCN has provided Marine Mammal Stranding Response Training Workshops in the Eastern Caribbean as well as the French and Dutch Antilles.

Abstract:

1. Killer whales Orcinus orca are found in all oceans of the world, but most of our knowledge on the species comes from studies conducted at higher latitudes. Studies on killer whales in the Caribbean have been scarce.

2. We compiled 176 records of killer whales from the Caribbean, including 95 previously unreported records and 81 records recovered from the literature, consisting of 27 capture or kill records, 4 stranding records and 145 sighting records.

3. Our results indicate that killer whales are widespread in the Caribbean Sea and can be found year-round in the region. Mean group size was 3.7 animals. A diversity of prey items was recorded, including sea turtles and marine mammals and possibly fish. We cannot exclude ecotype or morphotype-specific dietary specialization in the Caribbean population. A preliminary morphological analysis of 10 characters in 52 individuals from 21 different groups suggests that Caribbean killer whales do not represent any of the four Antarctic and subantarctic types, type 1 from the northwest Atlantic, or ‘resident’ and ‘transient’ killer whales from the northwest Pacific. Some Caribbean killer whales share a combination of characters typical of type 2 in the North Atlantic, whereas others share those typical of ‘offshore’ killer whales in the northwest Pacific. The significance of this is unclear. Comparison of Caribbean killer whales to previously described morphotypes and ecotypes is hampered by the lack of detailed, quantitative data on variation within other types, as well as by the lack of comparisons of genetic diversity.

4. Our study adds to the growing knowledge of the diversity of killer whales worldwide but underscores that additional research is warranted in the tropics. 

Summary:

Information on the distribution, abundance and ecology of marine mammal in the Wider Caribbean Region is scarce. This report aims at collating the on-going research in the Wider Caribbean Region, at identifying the most critical knowledge gaps that need to be addressed to inform and facilitate conservation actions and assess the most suitable research techniques to fill these knowledge gaps.

Numerous research activities aiming at marine mammals have been commenced by individual organisations as well as regional or even international collaborations throughout the Wider Caribbean over the past years. These efforts, ranging from visual to acoustic surveys, satellite telemetry, stranding response, and many more, provide valuable insight into important aspects of the ecology of marine mammals and show that the motivation and need to conduct research on marine mammals in the Caribbean waters is high. Due to lack of funds and capacity most current and past cetacean research in the region can be characterised as small-scale, low in sophistication, opportunistic, temporary and local which is a great limitation to the understanding required for proper conservation of this increasingly important resource in this tourism-oriented region. Consequently, if continued with the current level of capacity and expertise, the results will continue to remain limited. There is an urgent need to combine forces, work on a larger geographic scale and use new and innovative techniques if we want to move beyond the current patchwork in activities and understanding. Ideally, all on-going and suggested future research efforts should become integral parts of a joint international research strategy for the wider Caribbean.

The choice of research methods to be used, however, depends in large part on the questions to be answered. Knowledge on temporal and spatial scale of marine mammal occurrence in the Caribbean waters is essential for any effective management and conservation and should have first priority, followed by studies on the effect of anthropogenic activities on marine mammals. In the absence of adequate data on marine mammals in this region, but with cautious extrapolation of knowledge and experience gained in other parts of the world we suggest to concentrate research efforts on visual and acoustic surveys and monitoring, stranding networks and necropsy of stranded animals, along with photo ID and tissue sampling for genetic analysis. All these methods differ in terms of the aims for which they will be suitable. Therefore, the aims must be clear before choosing the method. Research on the diverse groups of marine mammals has to modular and collaborative such that it can be synergistic, provided that there is sufficient collaboration and communication between all parties involved.

Public outreach by involvement of local institutions, marine parks, tour operators as well as communication of any research plan and results to local, regional and international regulators, policy makers and public representatives, plays an equally important role in achieving management and conservation goals.

This report is part of the Wageningen University BO research program (BO-11-011.05-005) and has been financed by the Ministry of Economic Affairs (EZ) under project number 4308701020.