Weekly round-up: January 3

Coral reefs are a rich source of species diversity (Pixabay)

The 12th horizon scan has identified 15 emerging global biodiversity conservation issues, including deoxygenation and coral health, increased logging in response to fires and the use of seabirds to locate fishing boats operating illegally.

Published annually, the horizon scan searches for early signs of hazards and opportunities across the natural world, focusing on those that may require policy change or new strategies to mitigate or benefit from the resulting phenomena.

First on the list for 2021 is an underestimation of the effects of deoxygenation on coral health and survival. Cases of coral mortality due to hypoxic conditions have already been recorded in the Pacific, Indian and Atlantic oceans, but were primarily confined to coastal areas as a result of nutrient enrichment (eutrophication) or still waters in lagoons. However, warming due to climate change further decreases dissolved oxygen concentration, while also increasing oxygen demand from most species, further exacerbating depletion.

Writing in Trends in Ecology & Evolution, the authors note: “The value of coral reefs to humans, their high species richness, and their well-known vulnerability to increases in ocean temperatures and acidification suggest that any further deoxygenation could reduce reef survival substantially.”

Wildfires across North and South America, Russia and Australia made headlines this year due to the increasing frequency and intensity of events. While many policy proposals suggest removal of trees may reduce the scale of fires, there is little scientific evidence to support such action, while thinning trees and the proliferation of grasses and flowering plants in their place can increase fire risk.

However, the authors write: “In the USA and Australia, for example, media coverage of fuels management policies emphasised the potential that such policies not only could reduce the risk of extreme wildfires but could justify increases in logging … [and] extensive tree removal in the name of protection from fire may become increasingly likely.”

Could albatrosses and other sea birds help expose illegal fishing? (Pixabay)

Unreported, unregulated and illegal fishing is a continuing blight on the world’s oceans, but one solution could employ marine life in the fight against the destruction of their habitat. Researchers are exploring the use of tagged seabirds in locating fishing boats, including those that have employed tactics to avoid detection, such as switching off their GPS – preliminary studies in the Indian Ocean have proved successful.

The paper also highlights potential in the use of open-source investigations of environmental threats, citing the downing of Malaysian Airlines Flight 17 and poisoning of Sergei Skripal as successful cases of citizens and civil society providing vital assistance in the examination of significant cases.

Read the full list of emerging issues here.
Publication Trends in Ecology & Evolution

A fatal skin disease is afflicting coastal-dwelling dolphins (Pixabay)

Climate change has been identified as the cause of a fatal skin disease in dolphins, occurring when high volumes of rain from storms turn coastal waters into freshwater.

The disease, first noted following Hurricane Katrina in 2005 and afflicting approximately 40 per cent of bottlenose dolphins in the area, causes patchy and often raised, ulcerated lesions covering up to 70 per cent of the body. 

While dolphins are accustomed to seasonal changes in seawater salinity, the increasing frequency and severity of storms is causing rapid and dramatic drops in salt concentration, lowering the content to that of freshwater for weeks and months.

Dr Pádraig Duignan, chief pathologist at The Marine Mammal Center which, alongside Australian researchers, published their findings in the journal Scientific Reports, said: “As warming ocean temperatures impact marine mammals globally, the findings in this paper will allow better mitigation of the factors that lead disease outbreaks for coastal dolphin communities that are already under threat from habitat loss and degradation.

“This study helps shed light on an ever-growing concern, and we hope it is the first step in mitigating the deadly disease and marshalling the ocean community to further fight climate change.”

While the outlook for dolphins exposed to freshwater for long periods is poor, the authors also hope their research will be a key step in diagnosing and treating individuals affected.
Source The Marine Mammal Center
Publication Scientific Reports

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