Witte, R.H.

We here provide a synoptic overview and preliminary update of the marine mammals of the Dutch Caribbean EEZ based on 279 cetacean sighting and stranding records. The Dutch Caribbean EEZ is composed of two distinct sectors. One is centered around the leeward Dutch islands of Aruba, Bonaire and Curaçao (71,000 km2) while the other is centered around the windward Dutch islands of Saba, St. Eustatius and St. Maarten (22,000 km2). The previous principal review (of cetaceans) dating from 1998, was based on only 70 records from the leeward sector and confirmed the occurrence of some 13 species for Dutch Kingdom waters. Now, with a 4-fold increase in number of records, 19 species can be documented for the Dutch Kingdom waters (18 species in the leeward sector and 8 species in the windward sector).

The windward sector stands out for its large number of humpback whale sightings (45% of records) and may form part of its former (or current) calving grounds. This species remains relatively rare in the leeward sector (5% of records) and continues to be targeted by aboriginal fishing in its destination wintering grounds to the east, where the relict breeding population is having difficulty to rebound. The species is of growing interest to tourism in the region and urgently needs full protection from all fishing in the southern Caribbean. The leeward EEZ sector further lies down-stream from seasonal upwelling areas off Venezuela that support the largest fishery of the Caribbean. This sector stands out for its high occurrence of beaked whales and the Bryde’s whale. Marine mammal strandings are much more common here (26% of records) than in the northern sector (3% of records). Human induced mortalities (first suggested in 1974) and disturbance due to coastal tourism and recreation are key and growing concerns in the southern Dutch EEZ sector.

The marine mammal fauna of the Dutch Caribbean is evidently rich and varied but continues to suffer man-induced mortality and disturbance. Several nations, including the USA, the Dominican Republic and France, have recently established marine mammal sanctuaries in Caribbean waters. The Netherlands should consider doing the same.

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.