The
Science
Fish stocks threatened
Coral reef fish are threatened throughout the world from overfishing, habitat degradation and climate change. Many fish populations have been over-exploited to local extinction, and despite efforts to control fishing pressure, the future of our oceans appears bleak. Recently, scientists and governments have been focusing on creating and maintaining Marine Protected Areas (MPAs) to help protect fish stocks. However, these are usually based on geographical or human-imposed boundaries. The findings of Project NEMO will to help future MPA planners incorporate an understanding of the biology of the fish themselves into the reserve network design in the future. We hope this knowledge will improve MPA efficiency and effectiveness, and help prevent further reduction of fish populations around the world.
Expedition Aims
The aim of Project NEMO is to collect small tissue
samples from as many Omani clownfish as possible, and use these to extract DNA
on which we can carry out molecular analysis.
Analysis will involve examining sections of the DNA from each fish that
have variable pieces of coding called microsatellites.
These are normally sections of junk DNA, which don’t provide any
information that make up genes, so as a result they change within populations
much more readily than genetic code. This
variability varies from population to population, and we can use it to look at
the boundaries between different populations.
Rationale
It is vital for MPA and fisheries management to
understand how big a population is. ‘Big’
refers both to space (where the boundaries are; what splits populations) and
numbers (how many fish are in an interacting population).
From the genetic study, we can also predict how far the offspring of
resident adult fish are dispersed. This
is the information that is needed to design management strategies for
conservation or fisheries, including recommendations for where to locate marine
protected areas to best suit the biology of the fish.
We envisage this method being adapted to study fish around the world, and
this type of analysis improving the management strategies used to protect
vulnerable or over-exploited fish stocks in the future.
Why Oman?
The Omani clownfish is an ideal species for this study. It is endemic to Oman – i.e. it is found nowhere else in the world, which eliminates the possibility of fish travelling into the areas we will be studying from further a field. The 2000 km length of Omani coastline on which it is found has very few islands.
Amphiprion omanensis - Omani clownfish (from www.fishbase.org)
The Oman clownfish lives in shallow coral reef habitat. This means that we can study the entire species, and there are no populations that are inaccessible to us. The Omani clownfish lives with a host sea anemone, to which it retreats when approached. Using hand nets the fish can be collected and a small tissue sample taken without the fish being harmed.