Invertebrates need saving, too.

 

Two coral propagation tanks

It’s not only the charismatic species like sea turtles that can use our help.  Coral is only a tiny little invertebrate, but it’s an incredibly important part of marine ecosystems, and it’s having some trouble right now.  Stony corals build the reefs that harbor all sorts of life, from beautiful tropical fish to those sea turtles we talked about last time.  But between the rising ocean temperatures and human harvesting, many species of corals are classified as endangered, and almost all of them are threatened in some way.  Luckily, there are plenty of people who are willing to help out, like Bob Snowden, another aquarist at the Pittsburgh Zoo & PPG Aquarium.  He is involved with SECORE (SExual COral REproduction), a program that was started in 2002 in Rotterdam with the goal of improving knowledge of sexual coral reproduction techniques, as opposed to the more familiar asexual budding. 

Newly settled Tubastrea larvae (the bright orange spots)

Bob has always been fascinated by coral, and he brought the Zoo’s attention to SECORE in 2005, and luckily, was met with full support.  The Zoo became a member of SECORE in 2006, and in 2008, they participated in a field project for the first time.  That first year, the scientists and aquarists traveled to Puerto Rico to collect the larvae of the spawning coral, but since then, a permanent field station has been established in Curacao.  At the station, the focus is on the endangered elkhorn and staghorn coral, the primary reef-builders in the Caribbean.  These corals have a mass spawning event in August every year, and the scientists, including Bob, are ready to collect them and help them settle.  An extremely tiny percentage of the larvae settle, and even fewer survive past their first year.  It’s painstaking work, but it’s worth it to get even one polyp to settle. 

The 6-month old Tubastrea polyps

In the meantime, back at the zoo, Bob is working with a different species of coral in order to practice the techniques he’s learned with SECORE.  Captive-raised coral can be used in exhibits at the Pittsburgh Zoo as well as shared with other institutions, which lessens the need to take coral from the wild, so this work is also extremely valuable.  Today, in the coral propagation center (conveniently located in the same room as the sea turtles!), I was able to observe the tubastrea, or sun corals.  They started releasing their larvae nightly towards the beginning of this month, after not releasing any since October, and Bob has been diligently collecting them and encouraging them to settle.  Today we looked at 47 larvae collected on March 13 – 8 of them had settled, while 30 were still zooming around.  Even I was able to see these guys, as they are bright orange, but the elkhorn and staghorn larvae in Curacao are so small and colorless that they have to count them with microscopes.  “It can be a tedious process,” Bob tells me.  It’s important, but it’s clearly not for those without a lot of patience – even the 6-month-old ones were less than an inch tall.    

Luckily, the word continues to spread.  This past year, the zoo’s photographer, Paul Selvaggio, was able to head to Curacao for the spawning event, and the resulting photos have been presented to students and zoo board members alike.  As more people learn about coral’s plight, more and more of them will be inspired to help, which can only be good news for this amazing and versatile animal.