Marine mammals

Forty-one additional cetacean records are reported for the Leeward Dutch Antilles, expanding the list of documented records to 70 (53 sightings and 17 strandings). First records are given for the melonhead whale Peponocephala electra (Gray), such that now 13 species are confirmed for these islands. The most sighted whales are Bryde’s whale and shortfin pilot whale, whereas the most sighted dolphins are spinner and bottlenose dolphins. Most cetacean movement is upstream and towards the east/southeast. Reported strandings have been on the rise, of which 47% involved beaked whales (goosebeak whale and Antillean beaked whale)

A dead dolphin found on Bonaire in August 2011 is identified as adult Fraser’s dolphin Lagenodelphis hosei, a new species for the Dutch Caribbean. A first closer examination showed a collapsed lung, stomach parasite infection and abundant mouth ulceration as indications of its health status. The animal was relatively fresh and did not die very long before it was found. Like more often with stranded deep diving cetacean species within the area, remnants of crustacean were found in its beak indicating recent foraging. 

Abstract:

Based on the goals set forth in the Dutch Biodiversity Policy Programme, The Netherlands has a traditionally strong commitment to protect biodiversity and marine mammals both internationally and in its own national and Kingdom waters. Last year the responsible ministry, namely the Netherlands Ministry of Economic Affairs, Agriculture and Innovation (EL&I), developed a management plan for the biological resources of the recently declared Dutch Caribbean Exclusive Economic Zone. The Dutch Caribbean EEZ was formally declared on June 10, 2010, and amounts to more than 90,000 km2 of diverse tropical marine habitats. One of the key ambition coming forth from that plan was to develop a Dutch Caribbean Marine Mammal Sanctuary (MMS). This report provides the necessary review and background on which to base such an endeavour.

Our updated review establishes beyond doubt that the Dutch Caribbean EEZ has a rich and diverse marine mammal fauna which merits more extensive protection. Even though the fauna is only poorly known, based almost exclusively on incidental sightings and strandings, it amounts to a minimum of 19 marine mammal species, and possibly up to more than 30. Without exception, all documented species appear on protected species lists of one or more treaties ratified by the Kingdom, and/or its constituent countries. Large differences are apparent between the leeward and windward sectors of the Dutch Caribbean EEZ, both in terms of species composition and conservation issues. Throughout the region, cetaceans are playing an increasingly important role in island economies as an important natural attraction for eco-based recreation and tourism, and in this respect the Dutch Caribbean also possesses major potential.

We here propose the establishment of a MMS as the cornerstone to sustainable conservation and management of these charismatic animals. Ecological arguments for the establishment of habitat protection by means of the concept of sanctuaries are outlined, as are the many environmental issues that would eventually need to be addressed within the sanctuary.

Favourable pre-conditions for the establishment of a MMS in the Dutch Caribbean include the fact that

• a) all cetaceans are already have a legal status in the Dutch Caribbean EEZ which calls for actual protection,
• b) the most deleterious fishing practices are already significantly limited and controlled within Kingdom waters,
• c) the key enforcer, namely the Coastguard, is already strongly present (largely due to other reasons),
• d) the islands generally have a strong tradition of marine protected areas in coastal habitat,
• e) the incremental costs for research and enforcement needed to establish a sanctuary is modest,
• f) public support is high, thanks to the generally high level of development and awareness of the public,
• g) indigenous fishery practices do not conflict with cetacean conservation, and
• h) whale watching interests are only in their infancy.

Steps to establish a Marine Mammal Sanctuary (MMS) should include:

• Legal designation of the sanctuary is the first and most important step that provides the framework for all broader (international cooperation) and in-depth (knowledge and conservation development) initiatives.
• Once established, the fuller implementation of an MMS should be seen as a gradual process, involving development of knowledge, policy, rules and regulations, as well as public and stakeholder participation

Management Recommendations:

The following key action points are proposed to establish a Marine Mammal Sanctuary:

• a) Legal designation of the EEZ (one or both sectors) as MMS, along with establishment of legal guidelines for interacting with cetaceans (whale watching).
• b) Establish bonds of cooperation with sister sanctuaries in the region (France, USA, Dominican Republic), (e.g. regional stranding and sightings data network).
• c) Conduct baseline quantitative surveys of cetacean distribution and assessments in light of sources of deleterious sound sources and risks of vessel strikes.
• d) Review and adapt existing national and insular legal frameworks to improve these, preferably by developing separate and standardized marine mammals legislation.
• e) Develop information systems to promote the development of a whale (cetacean) watching industry.
• f) Train and equip marine parks and island veterinarians to conduct elementary autopsies and collect basic stranding specimens for analysis of causes of mortality, contamination levels and genetics, and link them to international academic institutions who will accept and analyse the specimens in regional context.
• g) Develop species action plans (e.g. humpback).
• h) Conduct cetacean surveys and management reviews every 5 years to assess marine mammal status and conservation progress.

Abstract:

In October 2011 an expedition took place to the Saba Bank, on board of the ship the Caribbean Explorer II. Main aim of the expedition was collecting data on underwater fauna and coral reefs. Apart from that data were collected on nutrients, water flow, sponges and seabirds and marine mammals. Data on the last group were collected by deploying acoustic data loggers, and by means of visual surveys. These visual surveys were conducted whenever the other activities permitted it. This cruise report presents an brief overview of the results obtained during the October 2011 survey. It contains a short day to day report, a full list of all birds, mammals and particular pieces of floating matter seen, and a brief presentation of the results. Furthermore the report contains a brief account of observed birds on Sint Maarten, since published accounts on the birdlife of the island are scarce.

Findings

Seabirds

• The seabirds most often spotted were the Brown Booby and the Magnificent Frigatebird.
• No marine mammals were observed.
• Red-Billed Tropicbirds were primarily spotted near the shore of Saba.

Birds on Sint Maarten

The first ever records of the following birds were made during this expedition:

• Cinnamon Teal (possibility of a hybrid cannot be excluded).
• Marbled Godwit (flying over the Great Salt Pond).
• A Merlin was seen hunting amongst Cliff Swallows and Barn Swallows.
• Three Ospreys were recorded.
• Breeding Caribbean Coots or adults with chicks were seen at several small ponds and in the salines.

Most Common (sighted>10)

• Cattle Egret (Bubulcus ibis)
• Snowy Egret (Egretta thula)
• Magnificent Frigatebird (Fregata magnificens)
• Brown Pelican (Pelecanus occidentalis)
• Black-necked Stilt (Himantopus mexicanus)
• Spotted Sandpiper (Actitis macularius)
• Carib Grackle (Quiscalus lugubris)
• Bananaquit (Coereba flaveola)

Least Common (sighted<2)

• Merlin (Falco columbarius)
• American Oystercatcher (Haematopus palliatus)
• Wilson's Plover (Charadrius wilsonia)
• Short-billed (Dowitcher Limnodromus griseus)
• Wilson's Snipe (Gallinago delicata)
• Marbled Godwit (Limosa fedoa)
• Whimbrel (Numenius phaeopus)
• Solitary Sandpiper (Tringa solitaria)
• Lesser Black-backed Gull (Larus fuscus)
• Cabot's Tern (Thalasseus acuflavidus)
• Eurasian Collared Dove (Streptopelia decaocto)
• Rose-ringed Parakeet (Psittacula krameri)
• Yellow-billed Cuckoo (Coccyzus americanus)
• Green-throated Carib (Eulampis holosericeus)
• Antillean Crested Hummingbird (Orthorhyncus cristatus)
• Northern Parula (Parula americana)
• Caribbean Elaenia (Elaenia martinica)
• Pearly-eyed Thrasher (Margarops fuscatus)
• House Sparrow (Passer domesticus)
• Northern Parula (Parula americana)
• Blackpoll Warbler (Dendroica striata)
• Prothonotary Warbler (Protonotaria citrea)

Notes:

The vessel that was used during this survey was not well suited for dedicated seabird and cetacean surveys. However, the gathered data fits in well with the seasonal pattern in observed seabird species and densities described for Guadeloupe for the same time period (distinct dip from August to October). According to Debrot et al, there are few records of cetaceans in October.

Abstract:

In December 2012 IMARES conducted workshops on the identification of whales & dolphins in the Caribbean on the islands of Sint Maarten, Saba and Sint Eustatius. Apart from giving the workshops, on-going cetacean projects, future monitoring needs and possibilities for extending monitoring projects were discussed together with the staff of the marine parks, government representatives and other local stakeholders, as well as with international research groups active in the Caribbean.

This report gives an overview of the occurrence of cetaceans in Saba, Sint Eustatius and Sint Maarten and describes the results of the cetacean identification workshops and the considerations with the local stakeholders. It also provides examples of existing on-going monitoring projects and an overview of research approaches that could be implemented on a local scale, or on a larger (national and international) scale in the future.

Management Recommendations:

Define monitoring need
There is a strong need to define what kind of monitoring is needed for both the near-shore areas (e.g. marine parks) and offshore areas (e.g. EEZ, trans-boundary regions). The best type of monitoring depends on the scale (Marine parks vs EEZ vs Wider Caribbean), the aims (e.g. long- term monitoring; estimation of abundance, biodiversity or distribution; risk assessment and conservation) and the available funding.

Coordinate and streamline current efforts
On a local scale cetacean monitoring has already started on the islands in different ways. The efforts range from the collection of any sightings made from land and water, to conducting effort related surveys in near shore waters. Some of these programs could be extended and coordinated between the islands. However, it is unlikely that the current staff would be able to do more than they are doing at the moment as they either need to have more staff or get long term assistance in the collection and analyses of the data.
A standardization of monitoring approaches between the different islands and the development and use of a common database would be helpful to allow the direct comparison of data. The new project idea to use handheld hydrophones on all three islands to monitor cetacean presence is a promising approach. However, close cooperation between local staff and IMARES and some long term funding is needed to ensure useful results will be obtained in the long run.

Extend monitoring efforts to a larger scale
Several people of the local staff of all three islands have been involved in the French AGOA surveys. This has provided them with more knowledge on cetaceans in the area, insights in data collection methodology and has also provided data for the Dutch Caribbean waters on the occurrence of cetaceans. The current protocols of the AGOA could be adapted and expanded to better fit the needs (to be defined) of monitoring cetaceans in Dutch Caribbean waters. A standard protocol for all areas could be a first step for a common database which could then be analysed on a regular basis. Following a similar survey protocol one could extend the AGOA survey in Dutch waters.
To obtain absolute abundance estimates of cetaceans in the EEZs of Saba and Sint Maarten, it is necessary to conduct designated surveys in the Dutch Caribbean waters using survey vessels or airplanes.

Risk assessment
In order to achieve an adequate conservation of the marine mammals in the Dutch Caribbean, information on species composition, distribution and abundance should be used for an assessment of the existing and potential threats to these cetaceans. 

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, Agriculture and Innovation (EZ) under project number 4308201083.