After a few days in New York enjoying Thanksgiving with my family, I’m now back in Jamaica. While I was away, Amber Stubler, a graduate student from Stony Brook University, was monitoring the experiment and making sure that water temperature, water flow rates, pH/CO2 levels and dozens of other factors were okay. The experiment is at the halfway point and I’m happy to report that it is going extremely well. Most of 360 sponge pieces or explants have survived. Two of the 6 coral reef sponge species I’m studying are comparatively less hardy, with a few explants dying, but differences in survival (and growth) between species are common. Although only halfway through the experiment, it does not appear that there are any major differences in survival between the 4 climate change treatments (see the blog “Climate Change Sponges, Jamaica: Experiment” below for descriptions). That is neither high temperature nor low pH seems to killing sponges, which is a very promising result for the future of coral reef sponges.
Declining salmon runs on the west coast of North America have triggered a cascade of fishery closures over the last few decades. Now, biologists are interested in seeing how the loss of salmon is affecting one of their top predators; grizzly bears.
The sponge pieces or explants are now healed and ready to be used in the climate change study. To determine the effects of warmer, more acidic waters (= lower pH) on coral reef sponges, we are comparing today’s environmental conditions to what is expected by 2100. But to determine what factor (i.e. temperature or pH) is most important for sponges, we are separating them into 4 treatments: 1) current temperature and pH, 2) current temperature and low pH; 3) high temperature and current pH; and 4) high temperature and low pH. Treatment 1 is called the control, as it is just the normal conditions of today. Treatments 2 and 3 will help us determine the individual effects of warmer water and lower pH. Treatment 4 mimics the predicted future environmental conditions of our oceans.
Monday afternoon I arrived in Jamaica to study the effects of climate change (warmer, more acidic waters) on coral reef sponges. Similar to the study examining climate change effects on a boring sponge (see previous blog), this study will be done in tanks on land. But this time we’ll be using heaters to warm the water and CO2 regulators and controllers to control the water’s pH. I had to buy all the necessary equipment in the USA and bring it with me on the plane. Arriving in Jamaica, the custom officers were very interested in my two bags full of aquarium supplies and I spent some time explaining why I needed 15 aquarium heaters and other assortments, but thankfully they let me through. After my colleague Marah Hardt arrived a few hours later, we got a taxi to the Discovery Bay Marine Laboratory. The following day was spent setting up some of the experimental equipment (which I will describe in a later blog), and today we collected sponges.
As climate change results in warmer, more acidic waters, all marine life is affected. Recent studies have determined that the effect of climate change on marine animals that have a calcium carbonate skeleton like corals, shellfish and pteropods will be severe, with the possible loss, for example, of many coral reefs by 2100. The effect of climate change for many marine animals, like sponges, is simply not known.