Welcome to the Marine Mammal and wildlife Research and Community Development Expedition blog where you can keep up to date with all the happenings and information from Kenya

Thursday, February 24, 2011

Ecologically important reef fish surveys

Recently, GVI has been trying to focus on assessing the ecologically important reef fish within the Marine Protected Area (KMMPA). We have been collecting this data from our snorkel transects for a few months now, and now want to refine it to focus on key species that provide an insight into the well being of coral reef communities.

Butterfly fish are recorded, as important indicators of healthy reefs

The first survey focuses on recording butterflyfish. A healthy reef is considered to be one which has a high abundance and biodiversity of coral species and Butterflyfish are well known to be bio-indicators of reef health, because many feed specifically on corals. The second survey focuses on a key relationship between Triggerfish, herbivorous fish and urchins on the reef. When triggerfish populations are exploited by over-fishing, sea urchin numbers increase significantly and compete for food with other herbivorous fish such as Surgeonfish (acanthurids) and Parrotfish (scarids). Herbivorous fish are incredibly important on coral reefs; their grazing prevents alga growing over coral and allows space for other benthic species to proliferate giving rise to biodiversity. Lower numbers of sea urchins allows more herbivorous fish species to be present, supporting reef biodiversity.

Surgeonfish are herbivores essential for maintaining algae growth

We aim to collect data from transect sites where the ecosystems are subject to different pressures of human and environmental impact in the hope to gain a better understanding of ecological differences, discovering biodiversity hotspots and realising areas which are under threat.