The loss of marine biodiversity is profoundly reducing the ocean’s ability to produce seafood, resist diseases, filter pollutants, and rebound from stresses like overfishing and climate change, according to a study published last month in the journal Science.

An international group of ecologists and economists has demonstrated that every lost species causes a faster unraveling of the overall ecosystem. Conversely, every species recovered adds significantly to overall productivity and stability of the ecosystem and its ability to withstand stresses. The study was based at the National Center for Ecological Analysis and Synthesis (NCEAS) at UC Santa Barbara.

“By choosing to measure the effects of species losses by their impacts on the things humans care most about, this study is the first to definitively link species losses in marine systems to their economic consequences for society,” said Kimberly A. Selkoe, co-author and postdoctoral researcher at NCEAS.

The good news is that the data show that ocean ecosystems still hold great ability to rebound. However, the current global trend is a serious concern: It projects the collapse of all species of wild seafood that are currently fished by the year 2050 (collapse is defined as 90 percent depletion).

The four-year analysis is the first to examine all existing data on ocean species and ecosystems, synthesizing historical, experimental, fisheries, and observational data to understand the importance of biodiversity on the global scale.

“Our results indicate that the current trend of losing marine species could have drastic consequences for what people can get from the oceans, but we also found that protection of ocean areas can restore these services,” said Benjamin S. Halpern, co-author and researcher at NCEAS. “In other words, it is not too late to help make things better.”

Lead author Boris Worm of Canada’s Dalhousie University said, “Whether we looked at tide pools or studies over the entire world’s ocean, we saw the same picture emerging. In losing species we lose the productivity and stability of entire ecosystems. I was shocked and disturbed by how consistent these trends are—beyond anything we suspected.”

Collapses are also hastened by the decline in overall health of the ecosystem. This points to the need for managers to consider all species together rather than continuing with single species management.

“Unless we fundamentally change the way we manage all the ocean’s species together, as working ecosystems, then this century is the last century of wild seafood,” said co-author Steve Palumbi of Stanford University. Beyond declines in seafood, human health risks emerge as depleted coastal ecosystems become vulnerable to invasive species, disease outbreaks, and noxious algal blooms.

Examination of protected areas worldwide show that restoration of biodiversity increased productivity four-fold in terms of catch per unit effort and made ecosystems 21percent less susceptible to environmental and human-caused fluctuations on average.

“The data show us it’s not too late,” said Worm. “We can turn this around. But less than one percent of the global ocean is effectively protected right now.