Study reveals 'sobering' decline of Caribbean's big fish, fisheries May 6,Sharks and other large predatory fish become rare on Caribbean reefs near large human populations. Dean Grubbs Sharks, barracuda and other large predatory fishes disappear on Caribbean coral reefs as human populations rise, endangering the region's marine food web and ultimately its reefs and fisheries, according to a sweeping study by researcher Chris Stallings of The Florida State University Coastal and Marine Laboratory. While other scientists working in the Caribbean have observed the declines of large predators for decades, the comprehensive work by Stallings documents the ominous patterns in far more detail at a much greater geographic scale than any other research to date. Fishermen typically go after the biggest fish first, but shift to smaller species once the bigger ones become depleted.
However, increasing effects of global climate change and other more direct anthropogenic disturbances appear to be increasing rates of coral mortality beyond those which can be sustained. The capacity of coral reefs to recover from successive disturbance events is potentially declining, due to continual declines in coral growth or reproductive output.
Coral reef recovery greatly depends upon disturbance regimes, reef characteristics, ecological characteristics, and anthropogenic influences Sandin et al ; Graham et al Disturbance characteristics can affect condition and recovery capacity.
Disturbances that kill the coral but do not affect the skeleton e. Ecological characteristics, such as grazing and scraping by herbivorous fish and urchins and high levels of functional diversity, can promote functioning ecosystems that will recover more rapidly from disturbances Bellwood et al Habitat conditions often expressed as the percentage of living corals and habitat complexity are also important because they underpin a series of ecosystem functions such as biodiversity and productivity of reef fish assemblages Coker et al.
Reefs exposed to high human pressure or in proximity to high human population centers may be expected to show slower recovery due to the likelihood of increased pollution, terrestrial run off and exploitation Sandin et al The Maldives consists of 26 atolls with ca.
Maldivian coral reefs are some of the more diverse reefs of the Indian Ocean hosting more than species of corals and species of fish Naseer and Hatcher, Disturbance regimes in Maldivian reefs have increased in recent years ranging from regular coral bleaching events due to increasing sea surface temperatures, destruction of coral reefs for land reclamation, increasing pressure on coral reef fisheries, increased sedimentation and eutrophication due to coastal construction, to crown-of-thorn starfish outbreaks Morri et al resulting in spatial variation in the recovery potential and condition of reefs McClanahan, ; Edwards et al ; McClanahan and Muthiga, ; Morri et al Three main uses of islands can be observed.
Since management regulation plays a key role mediating between conservation of functional roles and fisheries objectives Brown and Mumbyit is critical to provide managers with baseline information on current condition of reefs in fished and un-fished areas. This study tested the hypothesis that fished community and uninhabited islands were more degraded than un-fished resort islands.
We expected to find that coral cover, predator fish biomass and water quality would all be significantly lower in community islands than in resort islands, with uninhabited islands falling somewhere in between the two management regimes.
This study provides a detailed baseline of empirical data on coral reef benthic communities, habitat composition, coral reef fish biomass and ecological data for North Ari atoll in order to identify the role of anthropogenic and environmental stressors as drivers of the integrity of reef habitats allowing classification of reefs into different levels of health and human disturbance.
These data can also be useful for the evaluation and improvement of management actions such as the designation of and development of management plans for marine protected areas MPAs and marine managed areas MMAs.
This study surveyed 12 islands out of 27 islands in North Ari exposed to different human impact and management regimes four community islands: Rasdhoo, Bodufolhudhoo, Feridhoo and Maalhos, four uninhabited islands: Gaathafushi, Alikoirah, Vihamafaru and Madivaru, and four resorts: Velidhu, Kandholhudhoo, Maayaushi, and Madoogali Figure 1.
At each island reef, three sites were randomly surveyed close to the island and at each site, three replicate transects of 50m each were laid lengthwise along the reef slope 10 meters depthwith a minimum of 3 m separating each transect.
Map of the 12 islands exposed to different human impact and management regimes 4 resort islands, 4 community islands, 4 uninhabited islands in North Ari Alifu Alifu Atoll, Maldives. Benthic categories recorded included sand, consolidated rubble, turf, crustose coralline algae CCAfleshy macroalgae, hard and soft coral, and other benthic invertebrates e.
Hard corals were surveyed to the genus level and abundance number of individual colonies was recorded.1 Value of Coral Reefs & Mangroves in the Caribbean -- Economic Valuation Methodology V World Resources Institute January This document contains a methodology for assessing economic value of three goods and services.
Develop an understanding of the issues which are important to the development of the caribbean region and its DIASPORA. 4.
Develop the capability to investigate and report on issues which promote a better understanding of the Caribbean region and its DIASPORA. 5. Encourage a respect for Caribbean cultural diversity and identities.
6. A Field Guide to Coral Reefs of the Caribbean and Florida.
Houghton Mifflin, New York, pages: Knowlton, N., The future of coral reefs. PNAS, CrossRef | Lamb, J.B. and B.L.
Willis, Using coral disease prevalence to assess the effects of concentrating tourism activities on offshore reefs in a tropical marine park. Conserv.
One rationale for placing a dollar value on coral reefs is to gain political interest in preserving reefs; specifically by identifying, measuring and quantifying the economic cost of inaction and unsustainable practices (Cesar, H.
& Chong ). Studies in the Chagos Archipelago, Indian Ocean, indicate that, there, the core zone of a protected coral-reef area should encompass ha of diverse reef habitats if preservation of biotic diversity is the principal objective.
1. Research the earthquake activity occurring in the Caribbean and use a T chart to examine the positive and negative impact of an earthquake.
What are the primary and secondary effects of an earthquake? 3. Generate ideas of what people can do to remain safe during and after an earthquake. 4.