The stinging truth: jellyfish blooms of Abaco

Upside-down jellyfish in seagrass bed

Photo of Cassiopea jellyfish resting on top of seagrass in Abaco

We’ve all seen them before. Colorful orbs of goo that evoke different emotions in each of us: Panic. Wonderment. Fear. Joy…well, perhaps joy is a bit of a stretch. They are called jellyfish, and they are the study-subjects of on-going research being conducted on Abaco.

Why study jellyfish?

            Scientists across the globe have become increasingly concerned with studying jellyfish, as it appears as though humans and their impacts are driving “blooms” or increases in jellyfish numbers and size. Human impacts that are attributed with spurring these blooms on are global climate change, increased nutrient concentrations, overfishing, among others. Jellyfish are ravenous animals, and can consume great quantities of plankton which other organisms, such as fishes, also eat. Additionally, jellyfish can ‘blanket’ habitats and inhibit other animals from surviving in areas where  jellies thrive. Thus, human-mediated blooms of jellyfish can magnify effects already associated with jellyfish presence.

Jellyfish blooms of Abaco

            While scientists have predominately focused on pelagic, or open-ocean, jellyfish blooms and their effects on pelagic ecosystems, few have evaluated how benthic or bottom-dwelling jellyfish blooms affect the ecosystems in which they live. Abaco provides an excellent area to explore this topic, as there are several highly-human populated, and low-human populated coastal areas to conduct our research in. Additionally, Abaco is home to the upside-down jellyfish, or Cassiopea spp., a benthic jellyfish that is endemic to the wider Caribbean region. These jellies thrive in seagrass and shallow-water habitats, and have been found to be more abundant, and larger, in areas where more people live. This suggests that human-impacts to coastal ecosystems may be driving the blooms of jellyfish in these locations. We believe that high abundances and larger jellyfish may ultimately affect the abundance and diversity of other commercially and ecologically important organisms living in seagrass beds, such as fishes, invertebrates, and possibly seagrass itself.

 

Jellyfish invasion?

            Interestingly, Cassiopea spp., many not be the only jellies to bloom in The Bahamas. Anecdotal reports suggest that the painful Portugese Man O’ War have been found in higher densities in recent years. Further, there have been a few sightings this summer of several, rare Flower Hat jellyfish, Olindias spp., spotted in Treasure Cay by Peter Brind and friends. Although the identification has not been 100% confirmed, it would be an alarming sighting indeed, as the beautiful and venomous Olindias are endemic to Brazil, Argentina, and parts of Japan!

No matter what your reaction to jellyfish is (mine is a combination of happiness and itchiness), there is no doubt about it: jellyfish are here to stay. The only question is, how do we better mitigate jellyfish blooms and ultimately, what are the effects that jellyfish blooms have on Abaconian ecosystems?

By | 2017-12-01T14:05:46-04:00 October 4th, 2011|Categories: Mangroves and Creeks|Comments Off on The stinging truth: jellyfish blooms of Abaco

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