Page 72 - BBC Wildlife Volume 36 #06

LEMON SHARKS

FOR NOW,WE KNOWVERYLITTLE

ABOUTHOWSHARKSWILL
RESPONDASTHE OCEANS GROW

WARMER AND MORE ACIDIC.

Climate change is another threat that looms over the
lemon sharks, although at the moment no one really
knows how bad it will be for them. As shark biologist
Ian Bouyoucos points out, studies of the effects of
climate change on sharks lag far behind those looking
at bony fish. The reason for this generally comes down
to the difficulty of working with often very big, free-
ranging shark species.
Rising sea temperatures are likely to be a big problem.
“Sharks, for the most part, don’t regulate their body
temperature,” explains Bouyoucos. “So the higher the
for shrimp farming and coastal developments such as Top: shark water temperature, the higher the shark’s metabolic rate.”
biologist Ian
marinas and resorts – a big worry on the island of Bimini And with their metabolic rates running faster, sharks will
Bouyoucos (left)
in the Bahamas. “There’s a resort that wants to turn the and education burn more energy just to exist. This might mean that
mangroves into a playground, instead of leaving them programme other sources of stress, such as a lack of food, could easily
as fantastic larders for all sorts of different species,” says assistant Cameron push them over the edge.
Samuel ‘Doc’ Gruber, founder of the Bimini Sharklab. Raguse (right) fit For now, though, we know very little about how sharks
a radio tracker to
“The mangroves are important for far more than just – even well-studied ones such as lemon sharks – will
a shark at the
young lemon sharks,” he says. “As nurseries for fish, Cape Eleuthera respond as the oceans grow warmer and more acidic.
they’re the key to coral reef biodiversity.” Institute.Above: “How will climate change impact on these wonderful
Mangrove forests are bustling, biodiverse ecosystems the pair release fish, and how might it affect their distribution and
two tagged pups
packed with a broad spectrum of species, including the abundance?” Bouyoucos wonders out loud. “It’s a big,
back into the wild.
young of many fish and invertebrates that are important open-ended question.”
in local fisheries, such as snappers and lobsters. Gruber
is optimistic, though, that a proposed marine protected HELEN SCALES is a marine biologist, author and
area will finally be set up in Bimini to safeguard these BBC radio presenter. Her latest book Eye of the Shoal
vital mangroves and everything that relies on them. (Bloomsbury Sigma, £16.99) is out now.
72 BBC Wildlife June 2018