Marine hotspots under dual threat from climate change and fishing

A beautiful split image of a school of yellow butterfly fishes and the blue sky in French Polynesia

A beautiful split image of a school of yellow butterfly fishes and the blue sky in French Polynesia. Credit: Global_Pics/iStock/Getty Images.

GR: Nature rarely forms straight lines or even distributions. Global warming, just like biodiversity, is not even. The study reported below suggests areas that need our greatest conservation efforts. However, we have to try to save more than just the best areas. We also need to save some of the intervening regions.

The parts of the world’s oceans with the most varied mix of species are seeing the biggest impacts from a warming climate and commercial fishing, a new study warns.

“The research, published in Science Advances, identifies six marine “hotspots” of “exceptional biodiversity” in the tropical Pacific, southwestern Atlantic, and western Indian Oceans.

“Warming sea temperatures, weakening ocean currents and industrial fishing means these areas are at particular risk of losing many of their species, the researchers say.

Species richness

“From the cold depths of the Arctic waters to the colourful reefs of the tropics and subtropics, the oceans play host to tens of thousands of different species. But they are not evenly spread across the world.

“Using data on 1,729 types of fish, 124 marine mammals and 330 seabirds, the new study estimates how varied the species are in each part of the oceans. They call this the species “richness”.

“You can see this in the map from the study below. It shows an index of species richness, from the lowest (dark blue) to the highest (red).

marine-hotspots

Map of global marine biodiversity, using an index from zero (no species present, shaded dark blue) up to one (largest species richness, shaded red) representing 2,183 marine species. Map also shows the six marine “hotspots” identified in the study. Source: Ramírez et al. (2017)

“From this process, the researchers identified six hotspots where the number and mix of species is exceptionally high. These are outlined in the map above.

“The six hotspots are predominantly in the southern hemisphere. Three are closely packed together around southeast Asia (4), southern Australia and New Zealand (5), and the central Pacific Ocean (6). The other three are more spread out, covering Africa’s southeastern coastline and Madagascar (3), the Pacific waters of Peru and the Galapagos Islands (1), and the southwestern Atlantic ocean off the coast of Uruguay and Argentina (2).” –Robert McSweeney (Continue reading:  Marine hotspots under dual threat from climate change and fishing.)

Saving Caribbean Coral Reefs

Coral reefGR:  This post describes other threats to coral reefs beside increasing acidification.  The story includes an opportunity for citizen naturalists to help save Caribbean reefs.

By Jensi Sartin

“Beautiful Caribbean reefs have been a tourist attraction for decades, if not centuries. They teem with life, holding an amazing variety of fantastical fish and other sea creatures. But at the current rate, Caribbean reefs will be lost within 20 years. Worse, the damage is largely the result of our own actions.

“This dire news comes from the Status and Trends of Caribbean Coral Reefs: 1970-2012an extensive report from the International Union for Conservation of Nature (IUCN). The report explains that the direct threats from overfishing and land-based pollution are combining dramatically with the longer term effects of climate change to destroy a vital natural resource that lies just a short flight from the United States.

“IUCN used data from 35,000 surveys conducted at 90 Caribbean locations since 1970, and showed that reefs have declined by more than 50% since the 1970s. Its stark conclusion should give us all pause and another last chance to reflect back on whether our strategies to save our reefs are still effective—or a priority.”

Read more and learn how you can take part.