Tuesday, February 18, 2014

Blast Fishing

             Blast fishing is categorized into two main techniques of fishing, cyanide and dynamite fishing. Both of these techniques destroy the tropical aquatic ecosystems that are not easily renewable. Blast fishing destroys much of the coral reefs either by bleaching or by brute force. By destroying the habitat, it decreases the diversity of populations in the ecosystem. 98% of the Philippines’ reefs are being seriously threatened by human activity today, but blast fishing remains a top technique for fishing in the region.
Text Box: Dynamite Fishing in Tanzania

Dynamite fishing, as shown in the picture to the right, can be a very dangerous fishing technique. It can cause many accidents including loss of limbs to the fisherman. Coral degradation through destructive fishing practices states that dynamite alone is not the only thing used in blast fishing. Fisherman also use homemade bombs, potassium nitrate, gasoline, fertilizer, and sugar. Fisherman will throw lit dynamite into the open waters where fish live. This shocks the fish to where they float making it easier for the fisherman to collect the stunned fish. Dynamite fishing is inexpensive and effective. The bombs cost on average 1-2 U.S. dollars and they receive between 15 and 40 dollars for the fish collected. Blast fishing can destroy 10-20 square meters and large craters. In the Philippines, blast fishing is a widely used fishing technique.

                Cyanide fishing destroys thousands of hectares of essential coral reef habitats each year. Cyanide fishing is the process of crushing a cyanide tablet into a squirt bottle and squirting the solution into the water surrounding a fish. The fish becomes stunned from the poison to make it easier to capture. This allows the fish to be sold on the market alive. The market for live fish trade is booming, making hundreds of million each year. 50-60% of the trade fish from the Philippines and Indonesia are captured by cyanide fishing. Also 25% of aquarium fish are caught by cyanide and also 44% of tropical fish used for human consumption tested positive for cyanide.

                Fishing with cyanide may be great for the market but it is not good for the ecosystem. 330,000 pounds of cyanide are put into the Philippine reefs every year. This technique bleaches the corals and also effects other organisms in the environment. The recovery of corals from blast fishing is several hundred years, making this technique unsustainable.  There are laws against cyanide fishing but 14% of reefs continue to be destroyed each year in the Philippines.

Ways to prevent cyanide fishing include teaching the fisherman alternative methods of fishing and enforcing the laws more strictly,  promoting coral reef habitats by tourism, and also not buying tropical aquatic fish that have been caught by cyanide. Not ordering live tropical fish from restaurants helps lower the demand for cyanide fishing. Cyanide can be tested in fish but it is not tested often. Testing more frequently would help to catch the fisherman using this technique and fine them so they are less likely to use cyanide fishing again. To help preserve the reefs and ecosystem diversity, set up private areas where fish farms and coral can grow without the immediate danger of blast fishing.


  1. I found a literature paper that reports on a study of Indonesian reef recovery after blast fishing (Fox and Caldwell, 2006, Ecological Applications). They report on details from plots in different circumstances, but here is one key statement from the abstract: "extensively bombed areas showed no significant recovery over the six years of this study, despite adequate supply of coral larvae."

  2. I didn't know that fishermen used cyanide to 'stun' the fish. I only knew about the dynamite. As you mentioned in the article, these methods are cost-effective to the fisher, but are very bad for the environment. Do you think that there is hope to educate the fishermen, or will they not care and keep on using these methods to make their quota?