We knew today was going to be a good one as soon as we left our dorm.  The smell of pancakes wafted over campus, and soon we were tucking in to the breakfast of champions.  Our group was set to go snorkelling, hunting lionfish over reefs.  Yesterday’s group hadn’t spotted any – a positive sign for the native fish! – but we remained hopeful for a sighting.  After a quick safety talk (don’t spear each other with the equipment) we headed out on the boat.

Mask, snorkel, and fins on, we splashed overboard into the jewel-bright water.  Below the surface was an extraordinary sight – fish, brain corals, sea fans, all laid out and ripe for exploring.  We buddied up and spread out, in theory searching for lionfish hiding in crevices, but often forgetting our task as we admired our surroundings.  Highlights were huge spiny lobsters, beautiful queen triggerfish and a Nassau grouper, a species threatened by overfishing.

Photo credit to Montana Caller

We could have stayed all day, but eventually clambered back onto the boat and headed to the next spot.
This reef was formed on rocks scattered over the seabed, causing little clusters of life surrounded by channels of bare seabed.  Here we saw a barracuda resting near the sand – and finally, hiding in a rocky niche, a lionfish!  One of our group dived down with a spear – then came a cheer muffled by half a dozen snorkels as he successfully caught it!  Triumphant, we returned on the boat for lunch.

Photo credit to Montana Caller

A further two lionfish had been brought in by local fishermen – they are paid well to catch lionfish, helping to keep their numbers down.  Venomous spines cut off, we examined and dissected them.  The first thing we noticed was their enormous gape – their mouths unfolded like a pop-up book to allow them to swallow their prey.  We also admired their bright markings, camouflage so they aren’t recognised as a threat.  Poking around inside, we found crushing teeth, a tiny brain and a stomach containing the remains of a small fish.

Hands thoroughly washed, we bagged the scraps and cycled to the marina.  Just a few fishy chunks in the water attracted five nurse sharks, along with the remora which normally travel with them.  We watched the creatures circle through the water, agile remora often outmaneuvering the larger sharks to feed!  Nurse sharks are fairly slow-moving, as they are adapted to cruising along the seafloor to pick up whatever fits in their surprisingly small mouths.

No lionfish scraps for us; we had pizza for dinner, then a lecture on coral reefs.  The speaker pulled no punches when outlining just how much of a state they are in today – apparently the reef on which we dived is just a shadow of its former self.  This is due to a depressing cocktail of human interference through overfishing, tourism, pollution and historic misunderstanding of how the reef ecosystems work.  Essentially, it was believed that the vast numbers of fish eggs produced would repopulate any fished reef, but we now know that very few fish make it to adulthood due to high predation levels.  To make matters worse, mangroves, where fish are safer from predators and so more likely to reach maturity, have been decimated to build seafront hotels and so on.  The impact humans have had on the reefs meant that they couldn’t recover from natural disasters such as a hurricane and a disease in the important grazing species, the sea urchin.  Algae has taken over and corals, shaded out and poisoned by these fast-growing plants, are declining.

Photo credit to Montana Caller

Efforts to restore reef ecosystems usually focus on creating Marine Protected Areas around them – no-fish zones which allow creatures to grow to full size and reproduce, so the reefs can be repopulated.  Recovering herbivorous fish would eat the algae so that coral can grow once again.  But – and this is something I’d never heard before – it’s not working.  In something of mic-drop moment, the speaker revealed a predator new to the reefs which was preventing fish from reaching adulthood even when humans didn’t fish them… The lionfish.

eo271    January 6th, 2018    Bahamas    , , , , , , , ,

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