Photo credit: Joseph Pawlik Lab, UNCW
It’s pretty surprising in this day and age we know so little about such big things under the sea. You would think we would know everything that we would need to know, everything about this planet.
That’s Joe Pawlik, a marine biologist at the University of North Carolina, Wilmington. He talked to us about giant barrel sponges growing on coral reefs in the Caribbean. Pawlik refers to these sponges as the ‘redwoods of the deep’ because they resemble trees in their enormous size. He told EarthSky:
They do remind you somewhat of trees. They’re massive. You can fit a diver inside the cavity that’s in the center of particularly large individuals. [These sponges] are among the oldest things that we know about that are living on the planet.
Pawlik said that – since the year 2000 – the giant barrel sponge population off the Florida coast has grown by more than 40%. And as the sponge population grows, he said, corals are declining.
As the coral populations decline, sponges obviously have less competition. Potentially the sponge cover could be greater because the coral cover is being reduced by other things.
Pawlik said that increasing CO2 in Earth’s atmosphere acidifies and warms ocean waters, which will impact marine life. He said:
When people talk about needing to go to space because we already know what’s going on on this planet, that’s not necessarily true. We have a lot to learn and, particularly, a lot to learn in the ocean’s depths.
Pawlik said his team is the first to do comprehensive research on the dynamics between barrel sponges and corals on the Caribbean’s reefs. Coral reefs make up a very important part of the economy for the Caribbean – they are important habitats for food sources such as fish and lobster and protect tropical shorelines from erosion. Pawlik said that coral reef tourism also economically impacts local communities.
Coral cover is decreasing and there are a lot of arguments about why that’s occurring. They range from very cold winters to global warming and climate change causing bleaching of corals.
Pawlik said that animals like corals depend on saltwater to secrete their underlying coral skeleton in order to change it into limestone. Meanwhile, Pawlik said, sponges have a skeleton that is made of glass.
As the oceans become more acidic, it’s harder for corals to make their skeletons, but sponges don’t make those skeletons. This may be why sponges are flourishing in the Caribbean.
Sad.
Dear Joe Pawlik,
We can do better and I trust we will………..soon.
This is only a guess, but I imagine you would agree that human population dynamics are common to the population dynamics of other species like sponges. If so, this does not necessarily mean that the human species WILL NOT choose to do the right thing by doing things sustainably some day. Given the singular gifts of humankind among the species (ie, the splendid gifts which set the human species apart from other species), productive adaptation and behavior change that reasonably and sensibly conform to the practical requirements of biophysical reality can be chosen. Such change could have been chosen 100 years ago or 30 years or now. And if not now, perhaps human behavior change toward sustainability will be chosen soon enough at some time in the future, before the human species follows the fatally flawed example of arrogant greed-mongers among us who adamantly advocate and egregiously condone the relentless dissipation of Earth’s resources, the reckless extirpation of its biodiversity, the irreversible degradation of its environs, and the effective ruination of our planetary home as a fit place for human habitation.
It appears to me that the human species is singularly suited to adequately enough make necessary changes in its behavior repertoire so that its current global overconsumption, overproduction and overpopulation activities are modified in ways which do not lead to unimaginably unwelcome outcomes such as we can already foresee on the horizon. The catastrophic consequences for the human species that could plausibly result from its idolatry and wicked embrace of unbridled greediness such as is evident among worshippers of wealth concentration and power in so many places on the surface of Earth. This rampaging greed takes its shape in the many forms of personal gluttony, conspicuous per-capita overconsumption and obscene individual hoarding by a fortunate, tiny minority of people whose leadership have proclaimed that they are Masters of the Universe. They are easily identified by their concern for and positiive regard of no others but themselves, benefactors and cronies, all of whom are dodgy operatives and principal beneficiaries of the Great Global Greed Machine {aka humanity’s global political economy}. It is difficult for me to see how things will turn out well for children everywhere if greed-mongers continue to rule the world so absolutely as they do in our time.
Perhaps welcome change toward sustainability and a viable future for life as we know it is in the offing.
Always,
Steve
Some interesting information on here. Slightly off topic but I am so excited !. I saw Cats The Musical for the first time and the music and also the dancing is amazing. It is an emotional journey that all the audience gets involved with !. ‘Cats’ will make you laugh and smile and touch certain places within your heart. Everybody left the theater singing, content and uplifted. If you get a chance to go and see ‘Cats’ I really recommend it.
I recently did a report on sea coral. It truly is sad what is happening in the world’s oceans. Good article.
Dear : Mr. Joe Pawlick
Firstly, i’m impressed with your picture above. I have ever found the sponge such redwood in Leti Island, Eastern Indonesia. I found it in 15 metres depth and the diameter approximately 1 metre. The condition is still natural, and even the people do not ever catch the fish with bombs or even with toxican. The cliff is like walls and even make stairs. It is just little that i know, and i really enjoy with your article above.
Best regard