Wednesday, August 27, 2014

Plastics, where did they go?

Remember the fish you had for dinner?
Did it taste good?
Yes? Great!
But how sure are you that it's fish?

 Photo from: http://workjournal.archipelago.gr/?p=1607




According to Czar, Andrs et al., the size and quantity of plastics found in our ocean, as compared to what we introduce to the ocean, is way lower than what we expect it to be. But plastic don't just disappear from the ocean (I mean that would be great if it was that magical though). Czar, Andrs et al. gave four plausible reasons to such discrepancy. 


Shore deposition
 Photo from: Clean up the Coastline, Veraldarvinir 



Nano-fragmentation

Photo from: Current Biology, Wright et al.


Bio-fouling
Photo from: Bayview Slipway Marine Service


Ingestion
 Photo from: http://greensangha.org/2009/06/message-from-the-sea/


Each of these damages the environment in a way or another and are sources of concern but, particularly nano-fragmentation and ingestion affects us directly. 

Nano-fragmentation and ingestion comes hand-in-hand. Nano-fragmentation is where plastics are being broken down into smaller fragments all the way to a size so small that we could not see with our naked eyes, the resultant microscopic pieces of plastics are what we call "micro-plastic".  When we take into account these micro pieces of plastic, filter feeders and other organisms at the bottom of the marine food chain are affected. (Thompson et al., 2004)

Bio-accumulation may occur. This means that more and more micro-plastics are introduced up the food chain. A filter feeder eats 5 pieces of micro-plastic, a fish feeds on 100 filter feeders, a bigger fish feeds on 100 of such fishes, then it comes to our plate. That is 5 x 100 x 100 pieces of micro-plastic in a fish on our plate! 

So before you throw away a piece of plastic from your shopping trip, think again. A piece of this plastic may end up on your plate one day.



Literature cited:


Czar, A., Echevarra, F., Gonzlez-Gordillo, J. I., Irigoien, X., beda, B., Hernndez-Len, S., . . . Duarte, C. M. (2014, July 15). Plastic debris in the open ocean. Proceedings of the National Academy of Sciences of the USA.

Thompson, R., Olsen, Y., Mitchell, R., Davis, A., Rowland, S., John, A., . . . Russell, A. (2004). Lost at sea: where is all the plastic? 838.



Monday, August 18, 2014

Artificial reefs Woohoo!

According to statistics, approximately a total 86% of the world's coral reef is threatened, damaged or even destroyed (Wilkinson, C,2004) and humans are the catalyst for speeding up the destruction of coral reefs even further. Thankfully, before the remaining 14% gets threatened, we are already finding ways to salvage the situation.

One of the problems of coral reefs loss (other than scuba divers seeing nothing cool when they dive) is that coral reefs is home for massive marine biodiversity. Destroyed and damaged coral reefs are usually stripped bare of their marine biodiversity as they are no longer favorable living conditions. Leaving the coral reefs alone without stress would allow coral reefs to auto-repair but the process ain't going to be completed in a day or two.

I mean if i were a fish, I wouldn't prefer the top reef too.
Image by: Catlin Seaview


Man, being man, comes up with excellent solutions. Artificial reefs are introduced to provide marine creatures with "homes" and encourage coral reef repair.


Airplane purposely sunk as an artificial reef.
Image by: Jason Schappert
 Reef balls made of concrete.
Image by: Reef ball foundation

Why go with the traditional route of burying your dead body in 2m x 1m soil for or burning yourself so you can fit into that 30cm x 30cm altar? (these are Singapore dimensions by the way!)Instead of letting your dead body occupy space and rot, organizations like eternal reefs (http://eternalreefs.com/) allows you to pay to be part of the marine ecosystem by including your ashes into the concrete mixture when you die! (At a hefty price of course.)

It's not all a bed of rose though. Artificial reefs has its issues too.  The main component of reef balls is concrete and concrete synthesis produces carbon dioxide which contributes to global warming. Poor foresight and management when introducing such artificial reefs may backfire and cause further harm to reefs than benefits. For instance, the Osborne Tire Reef in the 1970s backfired completely. Instead of helping to augment two adjacent natural reefs, it ended up smothering and bashing into their fragile organisms.  When bonds tying the tires broke, tires were washed onto beaches, both expensive and time consuming to clean up. (Stephen Harrigan,2011)



The tires were too mobile and corals could not manifest onto them.
Image by: Navy Combat Camera Dive Ex-East




 I would think that artificial reefs is a great idea for a temporary solution before coral reefs regenerate themselves but much more study should have been done before the implementation to prevent later repurcussions.

References:



Harrigan, S. (2011). Retrieved August 18, 2014, from http://ngm.nationalgeographic.com/2011/02/artificial-reefs/harrigan-text/4
Wilkinson, C. (. (2004). Status of coral reefs of the world. In Status of coral reefs of the world (p. 301). Townsville, Queensland, Australia.: Australian Institute of Marine Science.