Cetaceans of Saba, Sint Eustatius & Sint Maarten: current knowledge and future monitoring

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.