Tag: Sea Life

Red Algal Bloom

Pearly Whirly Pearl Fact: Never Eat Oysters During These Months

Have you ever heard that you should only eat oysters in months with names that include the letter “R”? Turns out, there’s truth to the tale!

So why should you avoid eating local oysters in the months of May, June, July, and August?

Oysters are filter feeders that eat algae and plankton and are susceptible to a very specific type of algal bloom, or “Red Tide” that can occur during warmer months of the year. A buildup of toxins in the oyster’s tissue as a result of this algae can be harmful to humans.

So what’s an oyster lover to do?

The answer is actually quite simple. While this old rule is a word to the wise for those of us who like to gather our own oysters to eat from rivers and oceans, it doesn’t usually apply to commercially available oysters, which are strictly regulated by the U.S. government. You can rest assured that your favorite oyster joint is probably serving oysters that are algae free and delicious. Slurp!

Sea Sparkle

Sea Sparkle: Pretty, or pretty bad?

You probably aren’t too familiar with Noctiluca Scintillans, the alluring not-quite-algae responsible for the beautiful displays of light in the oceans surrounding Hong Kong. 

This unusual single-celled sea life, also known as “sea sparkle” gives off a bioluminescent glow when agitated, either by the movement of the waves or by a passing ship or fish. The breathtaking light shows are visible in many parts of the world, but become more prevalent in areas where increased nitrogen and phosphorous runoff from agriculture upset the delicate balance of the local ocean ecology.

Sea Sparkle

Noctiluca scintillans is an organism that functions both as a plant and an animal. While the organism in itself is not toxic, it tends to feed on phytoplanktons, and because noctiluca scintillans does not move from place to place, the buildup of excretions from its feeding results in high levels of ammonia in the surrounding water. This can lead to problems with surrounding sea life when heavy blooms of noctiluca scintillans take over large aquatic regions.

Noctiluca Scintillans single celled organism

We’re always impressed at the delicate balancing act our oceans perform to keep our entire globe running properly, and also by how easy it is for a few careless people to throw everything off kilter. Just a bit too much pollution from farms can cause seawater to become too nutrient-rich, leading to an overgrowth of noctiluca scintillans. The high ammonia caused by the overgrowth in turn causes problems with local sea life, problems which move gradually up the food chain until finally, they reach your dinner plate.

So what can you do about it?

Well, first, do your part. Be a responsible citizen of the globe. Recycle. Find ways to get involved. Educate yourself on the issues. Then get out there and make a difference! It takes a whole lot of drops to fill the ocean, and that ocean is depending on us.

Top Ten Most Wanted Continued (#1)

(This post is part of our blog series that deals with Pearls International’s take on social and environmental responsibility. For more information on how Pearls International gives back, please click here.)

We have finally reached the end of our list and hope you have enjoyed learning with us! Similar to Ocean Acidification, our top offender is an unseen predator. However, it is one in which the cause is still unknown, and treatment is impossible.

Dermo Most Wanted Poster

1) Parasitic Diseases
Causing a higher mortality rate than natural predators and ocean acidification, diseases such as Dermo and MSX come in at a landslide as #1 on our list. Perkinsus marinus, or Dermo, is a single-celled parasite that can multiply by hundreds of thousands. It is contagious and spreads easily because of the way oysters feed. Temperatures higher than 68 degrees Fahrenheit and high salinity can cause it to spread more rapidly. MSX, another parasitic disease, is similar in the way that it spreads and effects oysters, but requires higher levels of salinity to see the same rapid increase. These diseases get all of their nutrients from the oysters they infect. Diseases in oysters are nearly always fatal and kill within a year. Oyster beds can remain infected for 1-2 years before it is safe to repopulate them.

Top Ten Most Wanted, Continued (#2)

(This post is part of our blog series that deals with Pearls International’s take on social and environmental responsibility. For more information on how Pearls International gives back, please click here.)

As this series nears its end, we would like to talk about a huge offender to not just oysters and other mollusks, but everything that lives in the ocean. Not all threats are other animals, or even living organisms at all. Some of the most deadly predators are unseen.

Ocean Acidification Most Wanted Poster

2) Ocean Acidification
Ocean Acidification is a huge concern in the sustainability in our oceans in the not-so-distant future. Our oceans naturally absorb carbon dioxide, and their capacity to contain CO2 is not endless, as once was thought. The more carbon emissions we create (from excessive burning of fossil fuels), the more acidic our oceans are becoming. These increasingly acidic waters have a huge effect on our ecosystems, beginning in areas where water is shallow and slowly spreading outward. Oysters and other mollusks have trouble getting the energy to build up their shells, and many spats expend all their energy and die before given the chance. On the other hand, oyster predators such as crabs have adapted to grow thicker shells to defend against the acidic waters. Starfish have been documented to consume 20% more oysters when the oysters are submitted to acidic waters (as the animals will have thinner, weaker shells and be much smaller than healthy oysters.) With food supply for these predators getting shorter, the food chain in the ecosystems they reside in is becoming more and more off balance.

Top Ten Most Wanted, Continued (#3 and Counting)

(This post is part of our blog series that deals with Pearls International’s take on social and environmental responsibility. For more information on how Pearls International gives back, please click here.)

If you enjoyed last week’s blog, you may think you cannot be shocked any further by oyster predators.  Well – fasten your seat belts, because what you are about to read is even more shocking.

Starfish Most Wanted Poster

 

3) Starfish
Starfish are the largest natural predator of oysters and mollusks. A starfish population within an oyster bed can quickly consume 90% of young oysters soon after they have attached to the bed.

The Starfish’s methods are uncanny and frightening in an alien-kind of way.  Here’s how they operate:  A starfish uses its tiny tube-feet which cover his underside to grab ahold of the oyster. He holds the oyster near his mouth opening at the center of the star on his underside, then pries the shell open.  He inserts his stomach into the oyster – you heard that right – “into” the oyster – then releases digestive enzymes into the oyster to help break down its flesh.  Shocking, but true.

Some species of starfish swallow their prey whole instead, and break down everything from within.  Either way, we believe this particular oyster menace should be given Number Three (#3) on our Ten Most Wanted List.

Stay tuned for more unbelievable oyster threats, leading up to the Number One (#1) enemy of our beloved oysters.

Top Ten Most Wanted, Continued (#4 and Counting)

(This post is part of our blog series that deals with Pearls International’s take on social and environmental responsibility. For more information on how Pearls International gives back, please click here.)

This week’s seemingly harmless offender has a very interesting method of preying on oysters and other mollusks.

Sea Snail Most Wanted Poster

4) Sea Snails
Snails such as the “Atlantic Oyster Drill,” “Common Whelk,”and “Moon Snail” are some of the most creative predators of the oyster and other mollusks. Don’t let their harmless reputation fool you, these killers are dreaded by oysters and oyster farmers alike. Their drill-like tongues, called “radula” are studded with sharp teeth. They bore into the shell of the oyster, releasing acidic enzymes that help soften the shell as they drill. Once the drilling is complete, they extract and eat the meat inside of the shell. If you have ever seen a piece of shell or mother-of-pearl with small holes in the surface, it is likely that they were caused by one of these assailants.

Who knew those cute little snails were so deadly?  For sheer originality, the “Atlantic Oyster Drill” and the rest of its Sea Snail Gang earn the Number Four (#4) spot on our Ten Most Wanted List.

Stay tuned for more unbelievable oyster threats, leading up to the Number One (#1) enemy of our beloved oysters.

Top Ten Most Wanted, Continued (#5 and Counting)

(This post is part of our blog series that deals with Pearls International’s take on social and environmental responsibility. For more information on how Pearls International gives back, please click here.)

Today’s installment brings us to the next oyster criminal – meet the Flatworm.

Flatworm Most Wanted Poster

5) Flatworms
These are tiny offenders, growing only to a length of about one inch. They are hard to see because of their size and usually near transparent color, and that’s a good thing, because once you get a good look at them they are truly gross.  Flatworms have an appetite for the meat of the oyster and gain access by slipping their small, translucent bodies in between the oyster’s two shells, proceeding to feast on the live oyster from the inside!

Interestingly enough, intruders similar to the flatworm are more likely to cause an oyster to produce a pearl than the legendary “grain of sand.”  The oyster tries to prevent the worm from eating him by coating him with consecutive layers of an egg-white substance called “nacre” that crystalizes on the worm.  This puts a stop to the discomfort and forms a tiny pearl, however, only one in 15,000 of these type of natural pearls are high enough quality to go on the market.

Flatworms try to eat the oyster and themselves become a pearl – we like that reversal, however the audacity of trying to eat someone from the inside earns this breed a Number Five (#5) on our Ten Most Wanted List.

We hope you have enjoyed the information so far!  Stay tuned for more unbelievable oyster threats, leading up to the Number One (#1) enemy of our beloved oysters.  You wouldn’t believe what some oysters go through to deliver their beautiful pearls!

Top Ten Most Wanted, Continued (#6 and Counting)

(This post is part of our blog series that deals with Pearls International’s take on social and environmental responsibility. For more information on how Pearls International gives back, please click here.)

Many of the predators we’ve talked about in this series so far have been known to effect oyster farms and wild oysters much more severely than they do oysters in the protective facilities of pearl farms. This weeks offender is one that even pearl farmers can’t escape, and struggle to protect their stock from.

Barnacles Most Wanted Poster

6) Epibionts
Any organism that lives on the surface of any other living organism, including but not limited to barnacles, is an epibiont. Barnacles, while they appear harmless (and are harmless to many organisms) can damage oyster populations. Excessive barnacle growth on the shell of an oyster can prohibit that oyster from growing and developing properly. If the barnacles grow where the oyster’s shell opens, it can prevent the oyster from opening it’s shell to feed and breathe. Barnacle growth can also cause permanent damage to the shell, causing it to grow lopsided. This is especially detrimental in the pearling business, because a healthy oyster that grows at a consistent rate is key in producing pearls of the best quality.

Since barnacles can attach to anything, including ships, piers and rocks, we wish they would be more considerate about attaching to oysters.  Therefore, Number Six (#6) on our Ten Most Wanted List goes to the Epibionts.

Stay tuned for more unbelievable oyster threats, leading up to the Number One (#1) enemy of our beloved oysters.