Natural Resources Study: Seagrasses

In recognising the urgent need for fill for land development and the economic importance of the natural environment the Cayman Islands Government, in 1973, contracted a comprehensive natural resource study to “take into account the paramount need to maintain those features of the marine environment that are enjoyed by Caymanians and which attract tourists whilst at the same time not suggesting paralysing restrictions which would grossly interfere with the continuing process of development” (Wickstead, 1976).


It was the aim of the Natural Resource Study (NRS), which became known as the Wickstead Report, to make recommendations that “consider primarily those aspects of the marine biology of Grand Cayman most likely to be of direct or indirect economic and aesthetic value to the Island” (Wickstead, 1976). “and to provide a background of data for resource evaluation, development and conservation; it is thus a programme in applied, not pure, science, and the choice of topics for study and the assignment of projects (must be) in terms of this purpose and not of the intrinsic scientific interest of the area” (Stoddart, 1974).

Although the Wickstead Report’s purpose was to provide recommendations for what we now refer to as sustainable development of natural resources, it was also intended as a baseline survey that “should provide the means for Government to assess the influence of development project on the environment” (Wickstead Report, 1976). In an effort to fulfil these terms of reference a comprehensive survey of the natural marine environment was conducted that included an inventory of marine flora and fauna and an investigation into the physical oceanography of Grand Cayman, and for this purpose, Grand Cayman was divided into seven survey areas: North Sound and Little Sound, East End, South Sound, reef communities, littoral region, Great Beach, and Twelve Mile Bank

Because of its potential for real estate development, marl and sand extraction and the extension of leisure amenities, the NRS paid particular attention to the North and Little Sound. Located in the north-western part of Grand Cayman the North Sound is, by far, the largest lagoon in the Cayman Islands. It encloses about 90 km2, when measured from Barkers to Rum Point. The NRS team established 79 sampling stations in the North Sound. The autumn fieldwork took place from July 1974 to December 1974 and 37 of these sites were resurveyed for the spring data, between January 1975 and July 1975. They collected biological and physical data from each field station that included, surface water temperature, water depth, water clarity, sediment depth, the density of Thalassia was measured in a 1/4 m2 quadrat, algae collections and quantitative assessments. The marine angiosperm Thalassia testudinum was the most abundant seagrass found in Grand Cayman. With the most extensive stands occurring within the North Sound, Thalassia testudinum became the focus of the NRS seagrass study. Seagrass communities constitute one of the three major coastal interface communities in the Caribbean along with coral reefs and mangrove ecosystems.

Although there has been much research on seagrasses over the past 25 years, their valuable functions were well documented by 1976 and may be described as the following:

  1. Substrate stabilisation and sediment entrapment
  2. Provision of settlement area
  3. Provision of food
  4. Nutrient cycling
  5. Provision of shelter

Since the completion of the Wickstead Report the North Sound has been the focus of intense multi-use development. Dredging, filling and canalisation of the perimeter of the North Sound for development has given rise to the removal of mangroves, the in-filling of the tidal area, the concreting of the ‘soft’ coastal zone and the change in bottom topography by way of borrow pits etc. This development coupled with increasing tourism, recreation, and natural resource use (fishing for example) has meant that the North Sound has become a major multi-use area of Grand Cayman. Much of the findings of the Wickstead report are still referred to today, 25 years on, and such was the comprehensiveness of the report, that it forms the basis of marine research and coastal management in the Cayman Islands.

However, baseline surveys are in practice of use only if re-monitoring of the environment is undertaken from time to time and knowledge is continuously accumulated (Wickstead, 1976). Therefore in 2001 the Department of Environment revisited the Thalassia study of the Wickstead Report in light of 25 years of development. The updated study would discuss the quantitative changes in the North Sound Thalassia communities at the original Wickstead study sites, provide Thalassia density maps from the original Wickstead data and data collected in 2001 and suggest seagrass and water quality monitoring strategies for the future.

2001 Seagrass Report



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