Rise of the Jellyfish

Pink Jellyfish

On the Rise

While several marine organisms are on the decline, jellyfish populations are rapidly growing.  Jellyfish are found in every ocean in the world, and they are an indicator species.  According to Lisa-Ann Gershwin, the author of Stung! On Jellyfish Blooms and the Future of the Ocean, an abundance of jellyfish is a sign that the environment is out of balance.  When jellies flourish in an area, something is seriously wrong and trouble usually follows their arrival.  Recent blooms of jellyfish have been recorded in the Mediterranean, the Gulf of Mexico, the Black and Caspian Seas, the Northeast US coast, and in Far East Coastal waters.  Some in the scientific community remain skeptical of these population changes, but there are areas that are clearly experiencing an increase in jellyfish.  Some areas have also experienced a decrease or fluctuation in population size over decadal periods.     

Swarm of Jellyfish

            Several factors contribute to the increase of jellyfish populations including overfishing, pollution, climate change, and ocean acidification.  All of these factors create the perfect environment the jellies need to thrive.  Jellies are able to flourish in low oxygen environments that would suffocate other marine organisms.  They also have several methods of reproduction, which increases their population size quickly: hermaphroditism, cloning, external fertilization, and self-fertilization.  Their polyps settle in layers on hard surfaces and then detach when conditions are right.  The polyp stage can live indefinitely by cloning.  A polyp colony started in 1935 in a lab in West Virginia is still alive and growing today.  Also, jellies have long lifespans.  They can actually “de-grow.”  They are able to reduce their size while their bodies remain proportionate.  When food is abundant they are able to begin growing again.  

             One factor that is contributing to the boom of jellies is overfishing.  For example, at one time, anchovies were abundant in the Black Sea and off the coast of Africa.  Overfishing of anchovies, which compete with jellies for food, has led to an abundance of food for the jellies which then take over.  

             Another factor in the jellyfish population boom is pollution.  Trash and garbage polluting the ocean kills many jellyfish predators, such as sea turtles.  Man-made objects within the ocean, such as piers and boat hulls, provide perfect nursery sites for jelly polyps.  Another form of pollution affecting jelly populations is nutrient run-off, which leads to eutrophication zones.  These zones are areas that are oxygen depleted and provide a great area for jellies to thrive.

            Climate change, the warming of the oceans, is extending jellyfish ranges.  Warm water also contains less oxygen, which the jellies like.  Also, another impact to consider if ocean acidification.  Because jellies don’t have hard parts, they aren’t affected as much by acidification.

Impact

            Jellyfish consume a huge amount of food and will pretty much eat anything.  They have very efficient metabolisms and can put the energy they ingest toward growth.  One species (a comb jelly), Mnemiopsis, will gorge and continue to kill and collect prey even though it's no longer hungry.  A study showed that this species killed 30% of the copepod population that was available to it each day.    They continue to kill until nothing is left.

                  Jellies can have a large impact on important organisms within an ecosystem and can reduce biodiversity.  Mnemiopsis invaded the Black Sea via seawater ballasts and took over by the 1980’s.  Anchovies and sturgeon began to disappear in this area due to competition with the jellies for food.  The Mnemiopsis jellies made up 95% of the Black Sea’s biomass. 

Hope?

            A possible solution to the abundance of jellyfish: eat them.  Jellyfish have been part of the human diet for a long time in China.  In recent years the global jellyfish harvest has risen to 321,000 tons, and the harvested jellies are mainly consumed in China and Japan. 

            So much damage has occurred within the oceans that we aren’t sure what the future holds for them.  As said by author Lisa-Ann Gershwin, we must “adapt.”

Giant Nomura's Jellyfish

Resources

Jellyfish: On the Rise or Not?

Rise of jellyfish reveals sickness of world's oceans.

They're taking over!

Lionfish: The Unwelcomed Guest

Lionfish by Corbis

Everybody knows someone whom they don’t particularly enjoy being around. In the marine world, specifically the eastern coast of the U.S., this unwelcomed guest is the Lionfish. You may ask what does this fish do to make everyone hate them? Well for starters, this alien fish is highly toxic and likes to kill smaller fish and invertebrates. They are starting to become a major problem in the eastern U.S. because they are indigenous to the Indo-Pacific region and have few predators here. Therefore, nothing is keeping their numbers under control (besides humans). Allow me to explain their toxicity. The Lionfish has spines that it uses to sting its prey. When it strikes its prey, acetylcholine and a neuromuscular toxin are released. This can cause tremendous pain, respiratory distress, and even paralysis. (Lionfish Biology Factsheet). Because of these things, their invasion has led them to be considered one of the world’s greatest conservation issues (sort of a “Most Wanted” list). Basically these are some bad dudes!

The research article, “Invasive Lionfish Drive Atlantic Coral Reef Fish Decline”, gives a great insight into what effects the Lionfish are having on the indigenous fish in the Atlantic and Caribbean. There are numerous invasive species found throughout the U.S., but the article tells us that the Lionfish invasion is of “unparalleled speed and magnitude” (Green). In other words, we aren’t dealing with your average, run-of-the-mill, invasive species. In fact, the research done by Green et al., which was performed off of New Providence Island, Bahamas. Results from nine different coral reefs showed that “40% of the total predator biomass” was comprised of the Lionfish. That is a tremendous amount when you think about what percent this should be (zero: they shouldn't live there). Perhaps an even more shocking statistic is that in just two years there was a “65% decline in the biomass” of the 42 fish species in the Atlantic that fall victim to the lionfish. Whats more, the Lionfish were present in the Atlantic prior to 2008 when the latter report was performed. Therefore it is fair to assume that the total decline is greater than just 65%.

The graph above gives a good depiction of the native fish species biomass between 2008 and 2010. As you can see, the small-bodied prey had about 65% decline in biomass as mentioned, and the large-bodied competitors and non-competitors alike had a decline. Only the small-bodied non-prey species have benefited from the lionfish. This is probably because of less competition with other small-bodied fish and less predation by the large-bodied fish.

It appears that the lionfish is causing an underwater apocalypse and by this point your probably asking yourself if this is any hope? Well to be quite frank with you, we don’t know but its not looking good. The research article warns that the fish will have the same impact elsewhere in the Atlantic when it reaches the more northern waters. Additionally, when small-bodied prey become scarce they could go after the young from the large-bodied fish. All of these species of fish have their own niche and duty in the ocean and such a drastic reduction in biomass could be truly detrimental to the ocean. This is especially true when over-fishing, disease, toxins and other threats are impacting these species as well. Green et al. states that “given the geographic extent of the invasion, complete eradication of Lionfish from the Atlantic appears unlikely”, but it could be possible to keep them out of important nursery sites and protected areas. Some regions are actually giving prizes and money to people to catch these bad guys.

The fate of the oceans and lionfish is still yet to be determined, but with any luck their numbers will be controlled. For if not, their impact will be tremendous.

http://www.fishingunited.com/forum/viewtopic.php?t=11443

I told you these are some bad dudes. The picture above shows the wound from a Lionfish. The pressure builds up so greatly in the wounded area that typically the skin must be sliced open and  drained. As the picture shows.

References:
Corbis. Unknown in the Amercias 30 years ago, lionfish have multiplied at a rate that is almost unheard of in marine history. Picture. Visuals Unlimited. http://www.smithsonianmag.com/science-nature/invasion-of-the-lionfish-131647135/?no-ist

Green, Stephanie J., John L. Akins, Aleksandra Malijkovic and Isabelle M. Cote. “Invasive Lionfish Drive Atlantic Coral Reef Fish Declines.” PLoSOne 10.1371 (2012):Web.

Lionfish Biology Fact Sheet. NOAA, 31 May 2011. Web. 30 march 2014. http://oceanservice.noaa.gov/education/stories/lionfish/factsheet.html

The Forsaken Giant

Do you ever wonder what it is like to truly be alone; to be utterly incapable of finding anyone to share your time with? There is a whale swimming the Pacific ocean in complete solitude and is considered by many to be the loneliest creature on the planet. The reason for this is because of the fact that this particular whale communicates at a much higher frequency, about 52 Hz, than the average whale which communicates at much lower frequencies. Because of this the other whales cannot recognize this particular one and therefore it fails to find any companions.

The tale of the lonely whale dates back to 1989 when William Watkins of the Woods Hole Oceanographic Institute was sifting through audio recordings and recognized an unfamiliar frequency. From this point, more recordings of a similar nature were made especially by the Navy. Scientists say that it is incredibly easy to track this particular whale due to the strange frequency. Although this whale has been heard, it is still unknown as to what species it is due to a lack of a visual. It is speculated that the whale may be a cross between a fin and a blue whale causing the unique vocalizations.

It is assumed that the whale is consistently alone, and there is good reasoning behind it. This particular whale attempts to call and sing on a regular basis, but there is never a response. This whale is lacking the socialization that most require to thrive through the utilization of pods. It is broadcasting on the wrong levels, but it has the ability to receive the calls of other whales which is shown by the numerous attempts to respond.

This particular case appears to have captured the eye of Hollywood, as filmmakers and scientists are set to start some documentary work this fall. This is not the only attention that this whale has received. Although recordings have been taken for over 20 years, many individuals who have only heard the sad tale of the creature have been inspired. Many individuals have taken to writing poetry, songs, and literature about this whale.

References:

LaPointe, Leonard L. "Chapter 15: The Lonely Whale." Voices: Collected Essays on Language, Laughter, and Life. Clifton Park, NY: Delmar, 2010. N. pag. Print.

"The Loneliest Whale in the World?" DNews. N.p., n.d. Web. 28 Mar. 2014. <http://news.discovery.com/animals/whales-dolphins/loneliest-whale-in-the-world-130715.htm>.

http://files.abovetopsecret.com/files/img/as5283feed.jpg

Orca's in Captivity

   Each year, millions of people support aquatic theme parks such as SeaWorld without thinking of the negative effects these parks have on the organisms that live in them. One major marine mammal that is suffering due to a life in captivity is the Orca Whale. In nature, these creatures live in the open ocean with thousands of miles to travel every year. In captivity, they are forced into small living quarters that are not conducive to their development. In these forced environments, Orca's are shown to have shorter life spans with an average life expectancy of 30-50 years as compared to a life expectancy of 60-100 years in Orca's in the wild. You may have also noticed that Orca's in captivity have collapsed dorsal fins. This phenomena is a sign of an unhealthy Orca and is not naturally seen in nature. Below is a picture of an Orca in captivity with a collapsed dorsal fin, along with statistics on how many captive Orca's there are throughout the world.

     Just as the picture above states, keeping Orca Whales captive is not what nature intended. Many of us heard of the tragic deaths caused by a killer whale named Tilikum. This poor creature was only 2 years of age when he was stolen away from his mother in Iceland waters. Tilikum is now past 30 years of age and has been used to breed more than 54% of SeaWorld's Orca's, despite his aggressive behavior. It is no wonder, however, that Orca's in captivity become aggressive because they are forced into small areas that humans would view as bathtubs. If you were in a bathtub for 25 years, don't you think you would get a little psychotic? The story of these whales in captivity was put into perspective as the 2013 film Blackfish was released. This emotional film gained international attention as the sad story of Tilikum began to unfold. Although three human deaths have been caused by this animal, SeaWorld continues to hold degrading shows, almost acting as if these animals are merely a commodity. 

     In an effort to stop the captivity of these magnificent animals, one California lawmaker proposed a ban on Orca's in captivity, which could potentially outlaw Shamu shows in San Diego California (SeaWorld). The lawmaker states that there is no justified reason for the continued captivity of these animals. They are far too large and intelligent to be confined to such small living quarters. If this proposal were to be accepted, then all ten Orca's at the San Diego location are to be rehabilitated and returned to the wild where possible. Already, human preferences towards captive Orca's are beginning to change. This can be seen in the image below. 

     Due to lack of good human judgement, many Orca's have been in captivity for too long. Their health, life expectancy, lack of care, and living conditions are completely lacking in these man made habitats. SeaWorld sounds like a fun place to go, until we dig deeper and realize the inhumanity that occurs behind the scenes. To understand all of the hardships faced by Orca Whales, I recommend watching the documentary on Tilikum and many other Orca Whale's called Blackfish.

REFERENCES:

1)Cowperthwaite, G. (2013). Blackfish. Retrieved from http://blackfishmovie.com/about

2)Kirby, D. (2014, March 7). Calif. lawmaker to propose ban on orca's in captivity. Retrieved from http://deathatseaworld.com/?p=966

3)PETA. (2014). Seaworld of hurt. Retrieved from http://www.seaworldofhurt.com/

Dynamic Dolphins

Palm trees, sandy beaches, and blue water…Oh my! Doesn’t that just sound amazing? Well last summer (2013) I was lucky enough to experience all of those on a cruise to the Bahamas and it was absolutely wonderful. One of our stops on our trip was to Freeport, Bahamas. As most people know, when you stop somewhere while on a cruise, most people get off and go on excursions. My family decided to do this and I am so glad we did because it was probably my favorite part of the trip. You may not know this about me but I have an obsession with animals; mostly ones with fur such as dogs and cats, but I also am a big marine animal lover (one of the reasons I was dying to take marine biology). I love sea turtles and was actually able to swim with them when I went to Hawaii a few years ago, but one of my life goals had always been to swim with a dolphin. Well guess what? I can put a check mark next to swimming with dolphins on my bucket list because that life goal has now been completed! And let me tell you, it was amazing. We got to hang out with two male dolphins, who were brothers, and they were remarkably smart and cute.

                   This is a picture of me on the trip! 

This experience has only increased my interest in dolphins. I already knew dolphins are very intelligent animals known for their agility and playful behavior, but researching online I found out about an interesting study known as the Shark Bay Dolphin Project. It started in 1982 when two American researchers flew half-way around the world to a remote bay in Western Australia, at the Monkey Mia beach. There, they found a small group of wild bottlenose dolphins that would swim right into shore to be hand-fed by humans. From these few animals, their research expanded to include hundreds of Shark Bay dolphins, and their visit led to the establishment of an extensive long-term study of the population. The long-term records of the animals are being managed in a database at Georgetown University.

The main reason these dolphins are be researched is due to the unique window it provides into the dolphin society. From this research, the dolphins are being protected as well as providing information on the effects of provisioning on wild animals. Research performed includes hundreds of dolphins that are surveyed and cataloged each year. Their behavior, ecology, genetics, development, communication, and various other aspects are all being recorded, making this one of the most important dolphin research sites world-wide. What I also love about this is that it is all accomplished non-invasively, without tagging or capturing the dolphins. 

When looking at different articles about dolphins, an interesting aspect I came across is the mystery of why dolphins have evolved such big brains. Bottlenose dolphins have the largest brains outside of humans when body size is taken into account. Why do they need such large brains? The Shark Bay Dolphin Research Project has revealed that dolphins, like some large brained terrestrial mammals, lead highly complex social lives. Complex social relationships are thought to have played an important role in the evolution of large brains in elephants, apes, and humans, so it is believed to be the reason it is seen in dolphins as well.

Another study being performed in Australia can be found at Shark Bay, called the Shark Bay Ecosystem Research Project. Shark Bay is in remote Western Australia and is home to a large sea grass ecosystem. Its remote location and small human population have made it a safe place for organisms such as tiger sharks, sea turtles, and of course dolphins, to thrive.  

The male dolphins of Shark Bay are known to marine biologists for their social entanglements. Their relationships with each other are so unusual that one team of scientists argues that the dolphins live in a social system that is known to be quite unique among mammals. Researchers suggest that these complex relationships may stem in part from one simple factor: the dolphins' low cruising speed, which may lead to social smarts. Because the Shark Bay dolphin population is large and has overlapping territories, it doesn't take long for one group of dolphins moving at their normal speed to meet up with another, possibly competitive, group. In these situations, the dolphins are forced to do the two things that may enhance social cognition: make friends and form group alliances.

In yet another study, it was seen that dolphins have a large cerebellum and the findings from this research suggest this is due to motor and sensory processing. The scientists linked this information and sensory processing to echolocation (Marino). Echolocation is when high frequency sound waves are emitted by the animal and the echoes are picked up and rapidly processed.

So, it seems to be that the brain size of dolphins is still somewhat of a mystery. Is it due to social relationships, cruising speed, or echolocation? Although it may not be fully determined, it is no mystery how amazing these animals are. I hope the dolphins continue to thrive in these Australian waters. I also hope we get the chance to see them on our trip to the Outer Banks!

Here is a video I found of two dolphins playing near a boat, kind of scary how close they are! 

Reference:

Marino, L., Rilling, J.K., Lin, S.K., & Ridgway, S.H. (2000). Relative Volume of the Cerebellum in Dolphins and Comparison with Anthropoid Primates. Brain, Behavior & Evolution. Doi:10.1159/000047205

Snapping Shrimp: Louder than a gunshot

There is a small shrimp that belongs to a family of shrimp called the Alpheidae that is only about 2 cm long that can make a sound louder than a gunshot. It is called the Snapping Shrimp or sometimes the Pistol Shrimp.

Snapping Shrimp
http://aquaviews.net/wp-content/uploads/2009/09/snapping-shrimp.jpg

They stun their prey but snapping their claws together to make a crack at 218 decibels - which is louder than a gunshot. The sound stuns the prey and allows for the shrimp to go in for the kill. The noise is not caused by the claws hitting each other but by a jet of water that is created by the impact. The tiny stream of water spurts out at 60 mph which creates a low pressure bubble in its wake. When the bubble collapses it makes a bang louder than a rocket launch or a jet engine. Also for a tiny fraction of a second, the temperatures in the bubble can reach more than 4400C. The popping also creates a flash of light daily mail which lasts for about a billionth of a second. Rivals compete against each other by seeing who can make the loudest noise and if the larder claw becomes damaged in a fight, the smaller one grows to replace it. There are about 600 species of snapping shrimp world wide. (dailymail)

Signaling between snapping shrimp includes chemical and chela (claw) displays. Both males and females perform a visual signal which is an open chela display in both aggressive and pair-forming interactions. The shrimp responds according to the sex of the other shrimp and they use chemical signals to do it. Snapping shrimp are burrow dwelling and very aggressive in defending those burrows against same sex intruders. The larger animals most often win out but smaller animals have a greater chance of winning if there is a small difference is size. The interactions between same sex shrimp can get very dangerous and escalate quickly and can end up in serious injury of death. Snapping shrimp have asymmetric chelae and the size of the larger chela is proportional to the size of the shrimp. The body sizes of opposite sex pairs are highly correlated so body size is important when pairs are formed for the snapping shrimp. The interactions between snapping shrimp frequently begin with contact by one or more of the animal's antennae. They also bring their chelae into contact with the other shrimps body. The antennae are thought to transmit chemical signals important for pair formation by transmitting signals that have sex information. (Hughes)

Slow motion pistol shrimp attack

https://www.youtube.com/watch?v=QXK2G2AzMTU

The snapping shrimp is an incredible animal that has an amazing way of capturing prey. The fact that such a tiny animal can create such force is mind boggling. The way that the claw is shaped has a lot to do with how it is able to create a large bubble and make a deafening noise. They manipulate the flow of the water with their and are able to make the two parts of their claw come together and create a vortex of sorts in order to stun their prey. (Hess) They are a fascinating animal.

Sources:

Hughes, Melissa (1995) The function of concurrent signals: visual and chemical communication in snapping shrimp. Animal Behavior, 52 247-257.

http://www.dailymail.co.uk/sciencetech/article-1085398/Deadly-pistol-shrimp-stuns-prey-sound-loud-Concorde-UK-waters.html

Hess, David, Christoph Brucker, et al. (2013) Vortex formation with a snapping shrimp claw. Plos one.

Escape From the Cold: Spring Break on the West Coast!

While many people were emptying their wallets to go to the tropics and escape the harsh winter in Ohio, I went to Oregon to join Cassie after her grad school interview and to visit my uncle. While I was there, I decided to start collecting organisms for my BIO 215 project. The first stop was to Newport, Oregon. Being the wet season (rainy with high 40's and 50's) not very many people were there except the locals and fishermen. Newport is especially known for its history in fishing and their (to die for) seafood.

The touristy part of Newport is around the Yaquina Bay Bridge. This is one of the most iconic bridges in Oregon. The photo above is a better shot of the bridge in the later part of the morning. It usually is foggy or hazy around this time of year due to the heavy rain. Yaquina Bay is also were I started my collection for BIO 215.

I actually first started my collection when I saw these fishing "pots" or traps. I do not know exactly what you call them but I found quite a lot of on them. Don't worry, I did not steel any of the catch, just the by-products.

Here we have some acorn barnacles. I am certain these are Balanus amphitrite. I do not know much about them yet as I am still looking into it. I do know that these are a great nuisance to fishermen just like white-tailed deer are to us. Balanus amphitrite can damage pots, weigh them down, and actually cause them to float away in rare cases. Still though, how often do you see barnacles fresh out of the Pacific?

Recognize what's above? Blue mussels right? Rest assured they are but they are a little deceiving at first because they partly lack the blue shell we have seen in lab. Here is a better photo of what I found. When I started to go through what I collected back in Kettering, I was stumped as to what kind of mussels I had collected. There is a phenomenon called the Mytilus edulis complex. I learned of this trying to ID parts of my collection. It is basically were all the Mytilus species are interbreeding. However, after comparing freshly caught mussels with some sources, I confirmed they were in fact Mytilus edulis. Weather Johnson and Geller used PCR to ID their mussels to get around the Mytilus complex is unclear, but I can see why PCR is readily used in identifying mussels.

You know at Sea-World or the zoo you can only get so close to the animals? Well check this out!

"Be sure to get my good side."

I am not sure what the sea-lion is doing in the bottom photo, but it is kind of funny.

I have never been this close to sea-lions (Zalophus californianus). I have never seen them in the wild either. They look cute when they are pups, but not so cute grown old, huh? I hear in the news often that Zalophus californianus can be a nuisance animal. They can pile on private water craft, crowd docks, and do some damage to beaches. I am not sure what the reason is behind these floating docks. It could be management, or maybe tourism, but it was still great to see these guys up close. I believe Cassie and I were about 20 or so feet from them. Cassie also noticed a familiar organism under one of the docks. Think you know what it is?

If you guessed Robert Paine's keystone species Pisaster you are right! I almost missed this guy under the dock. My lens make his actual size a little distorted. It almost looks like his left arm is bigger than the rest of him. Thinking about it now, maybe there were some mussels under the dock and it was having is afternoon meal. Either way, got to see Pisaster!

I have to put this in here because I do not see this at all in Ohio as far as I know. Oregon State University (OSU) has their very own research vessel! OSU specializes in marine science, veterinary, pharmacy and toxicology.

Lets move onto my favorite thing about Newport. Think you know what it is by this photo?

If you can make out the symbol on the side of the right ship, it is docked at the brand new (2011) NOAA station in Newport, OR. This is a spin off from their Seattle station. I encourage you to check out those links. Not only are interesting and fun to read, they give a little deeper picture of what NOAA does. Here is the entry sign to their newest facility on the other side of the bridge. We could not go in because of 9/11 security. The fact that we got this close though was still awesome!

Below is a photo of the other ships. The NOAA sign above is about 15 feet to my left. Can you find the McArthur II?

There was a small sandy beach within walking distance from the NOAA entrance. I was able to collect some specimens there too. We found shells similar to a surf-clam but much smaller. It turned out to be a fine-lined lucine or Paravalucina tenuiscupta. You may be able to see a photo of it at the end of this post. It is small but it is there. The most amazing shell I found was a Batillaria cumingi shell. It had the iconic moon snail drill hole in it too! To think I almost missed this one because it was partly covered with sand! I took this photo when I was sorting everything.

Our last stop in Newport was a man made rocky shore. For being man-made, it was still cool to see. Cassie and I had lots of fun climbing on the rocks while we looked for more stuff to collect. Sadly, we found mostly shell fragments that don't make things easy to ID. Cassie did find one creepy looking sea-plant though.

Here are some more pics of the man-made rocky coast.

I am not sure what was on these rocks. The bottom one looks like a mix of algae and the other almost looks like a fossil.

Next stop was Lincoln City, Oregon. Almost all of Oregon's beaches are open to the public. If private beach owners open their beach to the public, the state will reduce their property taxes a good deal. Sometime private beach owners will only pay taxes on the house and not the beach itself! There was no indication this was a private beach. But check out what I first noticed (other than the lovely views).

Kind of makes you think right? What are your thoughts? It seems forever ago this happened and we are still dealing with it.

Lets just get back to the scenery shall we? Check out this coastal community. I also found lots of shells here. Big ones too. I hope this video works right. It does not look as good when I post it to the blog format. 

I am not sure what that flowing river/pond like opening is on the beach. We think it is more of a tide pool and it is is receding back into the ocean. The western gulls (Larus occidentals) were spending the most time around it. If the video does not work well, here are some photos of the flowing river/pond.

What I thought were blue mussels again actually turned out to be the even bigger California mussels (Mytilus californianus). Some of the shells I collected were over four inches long. My largest shell I collected was almost eight inches. You will see at the end of this post my overall collection. The last photo from our coast trip shows how rocky the Lincoln City Beach is.

Below you will find some pictures of sea-grasses we collected on the Lincoln City Beach. We briefly touched on sea-grasses recently in lecture. The first two are Zostera, or the "blade-like" grass. The next one is the "whip-like" grass Phyllospadix, or surf grass.

So to end this post, here is my overall collection from my week in Oregon (and some panoramic views).

The top photo is what I collected in Newport and the bottom is what I collected in Lincoln City. See what I mean when I said the California mussel was really big?

Top: Lincoln City Coast

Bottom: Silver Falls

Sources: 

Shells and Shellfish of the Pacific Northwest

Many Rows of Razor Sharp Teeth

I have always been fascinated by sharks.  They have a very powerful jaw and the reason why most people fear sharks is because they can bite.  I was surprised to find out that the shark with the most powerful bite is not the tiger shark or the great white.  Scientists from the University of South Florida report that sometimes the size of the shark can be misleading in respect to how strong they can bite.  Bull sharks have been shown to have the strongest bite with an average force of 6000 N in the back of their mouths and 2000N in the front.  Researchers know that the strong bite force is needed to crunch turtle shells.  They also think that it has something to do with the fact that bull sharks have a very high tolerance for freshwater.  Their bite strength may be needed for the things they consume in freshwater.  This jaw strength combined with their many rows of razor sharp teeth can lead to a painful bite into many other organisms in the ocean.

Sharks have as many as 5 to 15 rows of teeth behind their main row.  Their teeth are usually in functional service for about a week, but can be lost as early as 24 hours.  They can be lost so fast because their teeth are not attached with roots like ours.  As the main row is lost, teeth from the next row move in.

I have always enjoyed looking for these teeth along the beach.  I have been to the beaches of South Carolina about 8 times and usually find about 20-30 teeth each time I go that range in size and shape. In looking at the teeth I have collected , I wanted to learn how to identify what type of shark they came from.  I found this key that was helpful in determining what shark the tooth came from.  There are a number of other keys online.



I have found teeth from the great white, tiger, sand, lemon and bull sharks.  Hopefully we will have some time to search the beaches for teeth as a class on our trip!