Careless methods damage delicate marine ecosystems
Overfishing and mismanagement of marine resources is threatening the food supply of aquatic life and will ultimately hurt the economic viability of commercial operations, scientists say.
As aggressive harvesting shortens fish life spans, bigger fish are left with less food and the spiraling supply squeeze will leave future generations of fishers with smaller catches.
Joel Trexler, Florida International University professor and director of marine science, says careless harvesting methods of major commercial fisheries have killed their own futures and thrown coral reefs off their ecological balance.
Fishermen, he said, “may have earned high profits by having a quick, cheap harvest method for now.”
“But,” he said, “they screwed their kids.”
When people in the fishing industry don’t have jobs and when they can’t feed their families, Trexler said, they are more likely to make poorer and poorer decisions, creating a tradeoff between immediate economic benefits and jobs now and those in 20 years.
He said precautions need to be taken now, or future generations may lose seafood from their diets and opportunities for jobs in the fishing and fishing-related industries.
Even though limiting fishing now could restore fish populations to a more natural level and create jobs in the future, it’s a tough sell for those currently making a living in the industry, according to Michael Heithaus, associate professor and director of Florida International University’s s School of Environment, Arts and Society.
Using methods to improve a complex science “is also a social issue,” Heithaus said.
In popular recreational fishing areas like Miami, females have shorter odds of reaching their full life expectancies Trexler said, and that decreases the number of eggs being produced.
Trexler said he believes that while a depleting fish population is a concern, the situation is not desperate. People have control over future fish stocks.
With better fishery management and enforcement of no-fishing zones, Trexler trusts the oceans and rivers of the world can continue to be a rich seafood source.
Heithaus is also optimistic about future fish stocks, though he sees it important for society to understand the importance of the issue.
“We need to take precautionary measures,” Heithaus said. “If we don’t change the careless methods we have now, we won’t be in a good situation.”
In April 2008, Heithaus co-published with other scientists a research series for the Lenfest Ocean Program, which supports marine ecosystem research, on the effects of losing top ocean predators.
The number of top ocean predators such as sharks and marine mammals fell dramatically in the 20th century, by 90 percent in some regions of the world.
This loss has had major effects on the food chain. The predators’ prey can increase in abundance, which might reduce numbers of the species they consume. The same result can seep down through all levels of species.
Trexler said he believes it’s up to American citizens to choose political officials who are capable of balancing current economic concerns and the necessity to limit fishing and better manage commercial fisheries for a better fish stock in the future.
“I’m not a Bambi hugger,” Trexler said. “My interest and concern about fish ecology lies in the idea of sustainability.”