Thursday, March 06, 2008

Juvenile Shark at Semakau

Was rather delighted to hear the news that juvenile sharks were sighted by the people from Sport Fishing Association (Singapore) at Semakau. Check out ST's Manta blog for more details.

The Semakau guides and Team Seagrass have seen the adults a few times swimming in the Phase 2 lagoon, but guess the fishing people has a better chance of encounter the smaller ones as they are probably too small to be spotted by us from a distance. Fortunately, the sports fishing people practise catch and release, and thus impact on the fish population at Semakau is minimised.

The traditional anglers will normally bring the bigger fish the caught home for dinner, and the smaller ones will end up as fishing baits or thrown away. And unlike sports fishing that uses artificial bait, traditional fishing uses either live baits (like worms, fish etc) or dead baits (dead fish, squid etc) which may contaminate the water. Thus in a way, compared to traditional fishing, sports fishing causes less impact to the marine ecosystems.

Anyway, back to the shark. From ST's photo in his blog, it's probably a blacktip reef shark (Carcharhinus melanopterus), rather than a blacktip shark, which is usually used to refer to Carcharhinus limbatus. The former has a black blob at the tip of its pectoral fins and dorsal fin, while the latter's fins has a black edge. If this sound confusing, just do an image search on Google. Haha.

Anyway, the blacktip reef shark is one of the most common shark found in shallow waters in the region. However, even the local divers don't see it much, so I'll assume it's probably not that common in Singapore.

Blacktip reef shark are shy animals, and thus are generally considered harmless unless provoked.

This shark is also one of the few sharks known to do breaching (i.e. jumping out of water fully), like the whales!

Like other sharks, the population of blacktip reef sharks is also on the decline, probably because of the sharks fin industry, and also they were often caught with other fishes during commercial fishing and are usually wasted.

Hopefully if traditional fishing is prohibited on Semakau, we can establish a sizable population of these magnificent animals in our waters. And sighting juvenile sharks is certainly a good sign that these sharks are breeding in our waters, and are not just passerbys! :)

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