Many of the world’s fisheries are in crisis because of years of overfishing, pollution and habitat destruction. According to the United Nations’ Food and Agriculture Organization, 57 percent of global fish populations are “fully exploited” and an additional 30 percent are ”overexploited or collapsed.” This leaves just 13 percent in the “non-fully-exploited” category, down from 40 percent less than four decades ago.

The nonprofit Natural Resources Defense Council reports that many of the most popular fish, such as cod, snapper and tuna, are dangerously depleted yet continue to be overfished.

Fishing operations have only been able to satisfy rising demand for fish and shellfish in recent decades by using increasingly high-tech strategies like on-vessel refrigeration and processing, spotter planes and GPS satellites. Furthermore, said Matthew Roney of the nonprofit Earth Policy Institute, “Industrial fishing fleets initially targeted the northern hemisphere’s coastal fish stocks, but then as stocks were depleted, they expanded progressively southward on average close to one degree of latitude annually since 1950.

“The escalating pursuit of fish… has had heavy ecological consequences, including the alteration of marine food webs via a massive reduction in the populations of larger, longer-lived predatory fish such as tunas, cods and marlins,” Roney said. In addition, he says, sophisticated fishing techniques aimed at maximizing catches, such as longlines and bottom-scraping trawls, kill large numbers of non-target species such as sea turtles, sharks and coral.

Roney is optimistic despite the trends: “In several well-studied regional systems, multiple fisheries have bounced back from collapse after adopting a combination of management measures. These include restricting gear types, lowering the total allowable catch, dividing shares of the catch among fishers and designating marine protected.” He cited an example of Kenyan communities removing beach seine nets and creating “no-take” zones leading to an increase in total fish, fish sizes and fishing income. And no-take reserves established around parts of Australia’s Great Barrier Reef led to a doubling of fish stocks and size within the boundaries of protected areas and larger populations throughout the region.

“It’s not too late to get our fishing practices back on track,” reports NRDC. “Using smart laws, policies, incentives, and market demand, we can help sustain fish populations at healthy levels for years to come.”