Ecotourism

Summary

Coral reefs are a vital part of Curaçao’s economy, providing revenue from ecotourism and fisheries, as well as providing shoreline protection. A vital coral species, Diploria strigosa, is a major reef-building species around the island, and contributes enormously to the health of the reefs, making it a prime candidate for this project. Physical oceanic processes, such as waves and currents, influence the health of these corals by introducing oxygen-rich water through mixing of the water column. In order to understand more about the growth and vitality of coral around Curaçao, it is therefore critical to understand how these processes influence the movement of oxygen around coral reefs.

This thesis set out to collect field data to investigate the existence of a relationship between hydrodynamics and dissolved oxygen near coral reefs around the island of Curaçao, as part of a larger project, the SEALINK project. SEALINK, part of the Dutch Research Council (NWO)’s Caribbean Research program, is an interdisciplinary research initiative to assess the impact of land-based and water-borne substances on the coral reefs of the Dutch Caribbean. Through a fieldwork campaign, dissolved oxygen concentration, wave data, and current velocity data was collected from seven study sites on the southern coast of Curaçao. Acoustic Doppler current profilers (AD2CP) and oxygen loggers were deployed through diving, and left on the seafloor to measure for six hours. A statistical analysis was run to test the validity of using current velocities as a predictor for dissolved oxygen values. Finally, a computational fluid dynamics (CFD) model was created using the fieldwork data in order to assist in the understanding of processes that influence dissolved oxygen around coral reefs. The results from fieldwork show that the extent of the relationship between waves, currents, and dissolved oxygen depends greatly on the location and tidal cycle. Study sites closer to the eastern point of the island showed that velocity and dissolved oxygen are connected, and that velocity has a greater capacity to predict dissolved oxygen values. The CFD model assists in a deeper comprehension of the influence of flow and other processes that can impact dissolved oxygen fluctuations around coral reefs.

Abstract

Feeding wildlife as a tourist activity is a growing industry around the world. However,providing alternative food sources can affect wildlife ecology and behaviour. In this study,we combined animal-borne cameras onfive sub-adult green turtles (Chelonia mydas) from the Bahamas with a global review to directly assess impacts of provisioning on thebehaviour of an endangered marine species for the first time. Descriptive evidence from video footage, with videos included in the manuscript, showed that the tagged turtles spent 86% of their time in shallow water (<1.5 m) at a provisioning site. All individuals observed, both tagged and untagged, actively approached people and boats, with up to 10 turtles recorded feeding on squid offered by tourists at one time. During these feeding events, multiple accounts of atypical aggressive behaviour such as biting and ramming conspecifics were recorded. Furthermore, a review of online sources revealed the wide-spread significance of turtle feeding as a tourist activity in at least 20 locations within the global range of green sea turtles, as well as five locations with regular provisioning ofeither loggerhead (Caretta Caretta) or hawksbill (Eretmochelys imbracata) turtles. At the majority of the locations, turtles were fed animal matter such as fish scraps and squid. Although sample size limited quantitative analyses, we found indications of relatively high growth rates of two tagged turtles and low seagrass intake rates of all five tagged turtles.Therefore, our results emphasize the need to further investigate the impacts of turtle provisioning on natural foraging behaviour, ecosystem functioning as well as turtle growth rates and health implications. Supplemental feeding may increase habituation and dependency of turtles on humans with risks for turtle conservation. The innovative use of animal-borne camera technology may provide novel insights to behavioural consequences of human-wildlife interactions that can aid in the management and conservation of rare or endangered species

The Caribbean Sea is home to a diversity of coastal habitats that support the installation of three rich and complex ecosystems - coral reefs, mangroves and seagrasses -. There are also other unique formations such as stromatolites or blue holes. Oceanographic and climatic conditions allow homogeneous throughout the Caribbean basin to form a unit in terms of flora and fauna. This unit does not exclude an exceptional biological diversity, including species endemic to the area, which give the coasts of the Caribbean countries an ecological, landscape and some science. Recognition on the international and regional importance of the Caribbean Sea but also its fragile marine environment has allowed the Caribbean to gain its status as a natural heritage.

In addition to the ecosystem services it render (fisheries, coastal protection ...), the Caribbean Sea is a definite asset in the development of tourism in the area by the seaside as well as, more recently, ecotourism. The latter is generally based on marine protected areas and should facilitate the sustainable development of islands.

From a case study, the Saba Marine Park, the objective of this study is to analyze the relationship between natural heritage and marine ecotourism, as well as economic, social and environmental development of these resources.

Coral reefs worldwide are attracting increasing numbers of scuba divers, leading to growing concern about damage. There is now a need to manage diver behaviour closely, especially as many dive companies offer unlimited, unsupervised day and night diving from shore. We observed 353 divers in St. Lucia and noted all their contacts with the reef during entire dives to quantify rates of damage and seek ways of reducing it. Divers using a camera caused significantly more contacts with the reef than did those without cameras (mean 0.4 versus 0.1 contacts min-1), as did shore versus boat dives (mean 0.5 versus 0.2 contacts min-1) and night versus day dives (mean 1.0 versus 0.4 contacts min-1). We tested the effect of a one-sentence inclusion in a regular dive briefing given by local staff that asked divers to avoid touching the reef. We also examined the effect of dive leader intervention on rates of diver contact with the reef. Briefing alone had no effect on diver contact rates, or on the probability of a diver breaking living substrate. However, dive leader intervention when a diver was seen to touch the reef reduced mean contact rates from 0.3 to 0.1 contacts min-1 for both shore and boat dives, and from 0.2 to 0.1 contacts min-1 for boat dives. Given that briefings alone are insufficient to reduce diver damage, we suggest that divers need close supervision, and that dive leaders must manage diver behaviour in situ.