10%

Biodiversity and blue forests

Marine megafauna found in mangrove forests, seagrass meadows and saltmarshes

By Blue Forests Project

May 24^th, 2019

An exciting and surprising link between biodiversity and blue forests explored:

When we think of mangrove forests, seagrass meadows and saltmarshes, we don’t immediately think of shark habitats. But the first global review of links between large marine animals (megafauna) and coastal wetlands is challenging this view – and how we might respond to the biodiversity crisis. Mangrove forests, seagrass meadows and saltmarshes support rich biodiversity, underpin the livelihoods of more than a billion people worldwide, store carbon, and protect us from extreme weather events. We know marine megafauna also use these habitats to live, feed and breed.

Green turtles and manatees, for instance, are known to eat seagrass, and dolphins hunt in mangroves. But new associations are also being discovered. The bonnethead shark – a close relative of hammerheads – was recently found to eat and digest seagrass. The problem is that we're losing these important places. And until now, we've underestimated how important they are for large, charismatic and ecolgically important marine animals. A first review of the connections between marine megafauna and vegetated coastal wetlands proves more megafauna species use coastal wetlands than we thought.

Figure provided by Author to The Conversation

Before this review, the number of marine megafauna species known to use these habitats was 110, according to the International Union for Conservation of Nature (IUCN) Red List, which assesses species’ conservation status. After this study, another 64 species from 340 published studies, bringing the total number to 174 species. This means 13% of all marine megafauna use vegetated coastal wetlands.

In recent weeks, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) released a damming assessment of humanity’s stewardship of the natural world. Up to 1 million species were reported to be facing extinction within decades.

We need to dramatically change how we relate to and engage with species and their habitats, if we are to fix this problem. But the question is, how can we make global change real, relevant and feasible at local and regional scales? And, as the international community rises to this challenge, what information is needed to support such efforts?

This study suggests a critical first step to addressing the global biodiversity crisis is to deepen our understanding of links between species and their habitats. We also need to elevate how the evidence is used to both assess extinction risk and prioritise, plan and deliver conservation actions.

More than half of all coastal wetlands have been lost globally and the rest are at risk from a range of serious threats, including deforestation. There is an urgent need to limit and reverse the loss of coastal wetlands to stop biodiversity loss, protect communities and tackle climate change. Targeting places where high rates of mangrove loss intersect with threatened megafauna could lead to more efficient and effective conservation outcomes.