Overfishing
Overfishing is the taking of wildlife from the sea at rates too high for the fished species to replace themselves. The fishing industry in the Great Barrier Reef is second only to tourism in terms of income generation related directly to the Great Barrier Reef, bringing in an annual profit over $1 billion to Australia.
While the Great Barrier Reef Marine Park Authority has made the majority of areas of the reef off-limits for fishing with an emphasis on reef sustainability, it is still a huge drawcard not only for commercial purposes but for leisure/sport fishing as well. While many areas, techniques and species of marine life in the reef are protected by law, trawling for various types of permitted sea life like prawns and other molluscs inevitably leads to other species getting caught in the nets as a side effect, while the nets themselves can also damage the ocean floor and its inhabitants as a result of its “drag effect” – not to mention the additional pollution which enters the seas due to the general passage of so many fishing boats.
Overfishing has various negative effects on the Great Barrier Reef. The main issue with overfishing is that the species which is being fished does not have enough time to reproduce themselves, causing the number of that species to decrease. Since the ecosystem of the Great Barrier Reef is closely connected, the lessening of one species would greatly affect the numbers of others. If a herbivorous species of fish is overfished, then the number of algae around the reefs would increase. The number of carnivorous species would decrease as they then have a harder time finding food. Another effect that overfishing has on the Great Barrier Reef is the number of endangered species caught by accident by the fishing nets or trawlers. As these species are illegal to sell, they are often thrown back into the ocean and they often die in the process, further increasing the pressure on those species to reproduce.
Another effect that overfishing has on the Great Barrier Reef is the damage that it causes on the coral. When deep sea trawlers drag their nets through the reef, the net may get caught on the nearby coral systems. When the trawlers move, the coral is broken off as the net drags through the water. This increases the pressure on the coral to reproduce as they are already greatly affected by coral bleaching and crown-of-thorn starfish.
While the Great Barrier Reef Marine Park Authority has made the majority of areas of the reef off-limits for fishing with an emphasis on reef sustainability, it is still a huge drawcard not only for commercial purposes but for leisure/sport fishing as well. While many areas, techniques and species of marine life in the reef are protected by law, trawling for various types of permitted sea life like prawns and other molluscs inevitably leads to other species getting caught in the nets as a side effect, while the nets themselves can also damage the ocean floor and its inhabitants as a result of its “drag effect” – not to mention the additional pollution which enters the seas due to the general passage of so many fishing boats.
Overfishing has various negative effects on the Great Barrier Reef. The main issue with overfishing is that the species which is being fished does not have enough time to reproduce themselves, causing the number of that species to decrease. Since the ecosystem of the Great Barrier Reef is closely connected, the lessening of one species would greatly affect the numbers of others. If a herbivorous species of fish is overfished, then the number of algae around the reefs would increase. The number of carnivorous species would decrease as they then have a harder time finding food. Another effect that overfishing has on the Great Barrier Reef is the number of endangered species caught by accident by the fishing nets or trawlers. As these species are illegal to sell, they are often thrown back into the ocean and they often die in the process, further increasing the pressure on those species to reproduce.
Another effect that overfishing has on the Great Barrier Reef is the damage that it causes on the coral. When deep sea trawlers drag their nets through the reef, the net may get caught on the nearby coral systems. When the trawlers move, the coral is broken off as the net drags through the water. This increases the pressure on the coral to reproduce as they are already greatly affected by coral bleaching and crown-of-thorn starfish.
Fishing of snapper in the Great Barrier Reef using a trawler. As shown from the image, large amounts of fish can be captured in a short amount of time and this means that the fish have less time to reproduce. Continued fishing at this level would soon become unsustainable and fish numbers will become threatened. |