Few places are more closely identified with marine resources than small island states. From traditional fisheries to larger operations to the hundreds of millions of dollars ocean tourism reels in around the world, islands depend on healthy fish habitat and healthy fish stocks.

The topic has been the subject of a series of recent international meetings. Last week in Hawaii, Pacific island leaders met with U.S. President Obama and discussed marine conservation among other issues. In New York, negotiations continue on the Sustainable Development Goals and SDG #14 (conserve and sustainably use the oceans, seas and marine resources) is particularly central to that discussion.

Against that backdrop comes a report in Nature.com today that looks at how climate change is likely to alter the fisheries revenues of maritime countries in the future. The analysis uses “climate-living marine resources simulation models” and shows that global fisheries revenues could drop by 35% more than the frequently cited projections by the 2050s under high CO2 emission pathways.

Generations of evidence, beginning even before the impact of greenhouse gas emissions on the ocean was well understood, have shown that even small changes in the ocean can alter fish abundance and distribution. Today, fluctuating temperature, sea ice, salinity, pH, oxygen levels and circulation, is dramatically reshaping the global fisheries map. We know there has been a shift in potential catches toward cooler waters in higher latitudes and away from the tropics–the location of most island nations.

Furthermore, countries with few economic alternatives to fisheries stand to disproportionately lose out. For example, heavily dependent fishing countries like Tokelau, Tuvalu and the Marshall Islands face the prospect of deep revenue drops under a variety of possible emissions scenarios.

More research, particularly at the regional level, of both likely biological impacts and the economic consequences of the changes, is needed and some funds have already been earmarked for such assessments in the Pacific. But it’s a big ocean and even bigger changes are underway. The sooner we understand them and take action, the sooner we can help the marine system and the people who depend on it.