This year we made special arrangements to get some of our crew out to the island. Instead of catrching a flight over, we would be boarding the motor vessel Dollie and enjoying the three hour cruise to Bimini from Pompano Beach. We arrived at the dock at 7:00am and found the boat ready to get underway. The boat is owned by Pete Lindgren, one of the owners of Lindgren-Pitman, Inc. - a major fishing and aquaculture products company. He was hoping to test some new polymer mesh to see how "sharkproof" it was. Please see the "Tiger Beach" page (shortcut on top right) for a daily journal of those tests and BBFS work on adult lemon sharks. We loosed the lines and made our way into the intracoastal waterway. A few short waits for bridges and we hit the Atlantic Ocean. There was an east wind and it was a little choppy but the fifty-four foot Hatteras ploughed through the waves with authority.

We got a little wet going across the Gulf Stream, as there was a lot of spray from taking waves head on and we motored through a small rainstorm. The journey took less than four hours and we were pulling into the Bimini Sands marina. Once our clearance was finished we headed over to the lab and started to get settled in. After a good lunch, Doc gathered a few of us together and we picked up the LP guys to start some rounds of polymer mesh testing. We loaded a boat and headed out to Triangle Rocks where we frequently feed Carribean reef sharks. It was pretty choppy out, but we managed to set the anchors and position the boat right next to a big sandy cut we call "The Arena". Several sharks were circling the boat as we readied all our equipment.

As Doc started to throw bait to the waiting sharks, we attached bait to some mesh we had hung on an H-shaped frame. This setup allowed two people to hold the arm opposite the arm the mesh was strung along, and keep the mesh in the water. The sharks were pretty cooperative at first, making a few good runs at the aperatus and getting a few good bites onto the mesh. At one point, the sharks even wrestled the frame out of Pete's hands. After repeated abuse by the reef sharks the mesh was taken out and inspected. I had to admit I was pretty skeptical after seeing the sharks bite, shake, and twist the frame. We were all pretty surprised when the mesh came up virtually unscathed. The polymer didn't just pass the first test, it aced it cold.

With the test over, and the last piece of bait eaten, everyone slapped on their fins and eased into the water to swim with the sharks. Even Doc got in to enjoy the swimming sharks. We had brought the new Twin V boat out to do the work off of, and Doc gave it a thorough underwater inspection. The sharks milled around for a little while, looking hopeful for another free morsel of food. We went back to the lab with a very pleased LP crew. They went back to the M/V Dollie and we settled into the lab routine. Gear had to be cleaned and stowed, food was cooking, and we had to have a big staff meeting to plan out the details of the upcoming fieldwork. Within a few hours every piece of equipment was back in its place, and all the lab residents had full bellies and were briefed on our battle plan to catch and census this year's cohort of juvenile lemon sharks. Tomorrow will be the first night of fishing, and PIT 2008 will officially be underway.

Tonight PIT begins in earnest with the first overnight set of the gillnets in the North Sound area of the lagoon. There is a certain excitement in the air, as everyone is anxious to get out in the field and start catching lemons. We are all wondering what this year will hold and how our results will help weave into the greater story of lemon shark life history Doc has been trying to interpret and retell over the course of his distinguished career. The staff has convened and picked the two teams that will share the load of tasks to be completed during the PIT census. There will be an "away" team that will actually stay up overnight and catch the sharks and catch some sleep by day, and a "home" team who will cook, clean gear, and repair equipment during the day so that the away team is set to go when they wake up in the late afternoon.

The away team takes a nap in the early afternoon, and then gets up to double check their gear and pack personal items for the night out on the boat. Some items are must-have, including rain clothes and head-lamps. We fish through any weather except when there is lightening. Weather can sneak up quickly on you in the islands and having rain protection to stay fairly dry is pretty useful. Some others go the opposite way and just wear a full wetsuit, though they may stay soggy for hours. Headlamps allow you to see what you are doing at night, while still maintaining full use of both your hands - highly desireable when working with sharks. Some popular items include entertainment and walkmans and books were always the mainstay. The rise of compact mp3 music players has really come in handy. The tiny units and small, foldable speaker boxes can be found on almost every boat. Music helps to pass the hours and keep you awake between net checks at night. It is also a great way to break the ice and instantly bond with new team members you have not met yet.

The team gets out to the lagoon and every boat positions itself. We coordinate to the minute when all three nets hit the water and our fishing has begun. The first night proves to be exciting but still a bit slower than past years. A total of twenty-seven sharks were caught throughout the course of the night. This included seventeen recaptured and previously tagged sharks and ten newborn sharks. This is aprticularly interesting, as usually newborns outnumber recaps in the Bimini lagoon. The main reason for this is mortality, as many newborns do not make it past their first year in the lagoon. Tis pattern is a little strange and may indicate something strange is happening in the lagoon. We will have to see how the rest of the gilnetting plays out before we can begin to infer what is happening in the lagoon.

Although excited for the coming hours of tagging, the night started off quite slow. It took a full six hours after the initial set of our gillnets to catch the first shark, which was odd given that previous work has shown juvenile lemon shark catch rates to be highest two hours before and after low tide. We set our nets ready for prime time, but were ultimately disappointed. We only caught two more sharks throughout the remaining set, luckily it appeared that both individuals had fairly full bellies, and so these two were placed in a separate pen for “stomach eversion” procedures to follow in the early morning. In brief, eversions are performed to study the stomach contents of sharks that may have recently consumed prey items in the wild. Eversions have been performed extensively at the Bimini Biological Field Station in the past, and this work helped characterize the diet composition, and primary prey items of the lemon shark. It appears that Yellowfin Mojarra (Gerres cinereus) make up a large proportion of their diet. That said, this year’s eversions are being performed to genetically characterize the mojarras that lemon sharks consume, namely sequencing the major histocompatability complex (MHC) genes for all such fish found in the shark’s stomach.

MHC genes are intimately linked with immune defense and the ability to distinguish self from non-self at the cellular level. Indeed, MHC genes code for proteins that recognize and process foreign virus’, bacteria, and parasites in the body, and then present them to cytotoxic t-cells or b-cells to elicit an immune response. It is generally accepted that individuals with high diversity of MHC genes are able to respond to a wider range of pathogens, and are thus “fitter” in a Darwinian sense. That said, a general hypothesis that has never been tested in the wild is that apex predators (such as sharks) improve prey population growth rates by selecting for (and consuming) the weak and infirm, leaving only the strong to exploit the remaining resources. Our study system provides a rare opportunity to test this theory; by sequencing the MHC genes for fish found in shark stomachs, and comparing them to MHC genes from a random sample of fish taken from the same nursery lagoon, we can see whether sharks are preferentially feeding on MHC poor (and thus weaker and less viable) fish. Although this year’s work is indeed a pilot trial, sampling over the coming years should tell the complete story.

It was another slow night, as we only managed to catch one shark for the entire evening. Something must be going on here. Our total catch of 30 sharks to date in the North Sound lagoon is the lowest total in the 14 year history of the PIT sampling campaign. A few of the crew members are clearly perplexed, and grasping for answers to this anomaly in the patterns. Possible explanations include:

1) the environment has changed (and possibly degraded) since sampling in 2007.

2) given that we are seeing an average number of recaptures, but few newborns, it is possible that fewer adult females are being recruited to the nursery lagoon in comparison to previous years. This may be a natural phenomenon, or perhaps a few adult females succumbed to fishing pressure well offshore.

Our team is leaning towards the “low recruitment hypothesis”, as having two fewer adult females return for parturition means on average 25 fewer newborns in the population. Sampling in the Sharkland lagoon next week will provide some insight into these patterns.

Slow nights, such as these, however, also allow for bonding between the crew members, obviously to fill the time and quell the boredom. Some individuals become introspective at times like these, and attempt to reconnect with nature; it is often forgotten how the hustle and bustle of the urban jungle tends to drive us from our roots. The North Sound is certainly a beautiful place to spend an evening, surrounded by mangrove forests and large groups of egrets or cormorants; with little ambient light the skies are literally peppered with stars. Sunsets and sunrises are spectacular over the western and eastern shores, respectively, of the lagoon. Tears often well up into the corner of my eyes (although I usually blame it on the wind) as the sun slowly sets over the horizon, and the collage of wispy clouds refracts the radiant reds, oranges and yellows in all directions. No two sunsets are alike, and so each one brings something to this world that no human eye has ever gazed upon before. A truly humbling thought.

Today we will take a short break from fishing. This day of "rest" will allow us to repair gillnets and get a small respite from the long nights on the water. We will also switch people from the home and away teams so that everyone gets the chance to be out in the field and involved with the catching or tagging of lemons. Most of the lemon sharks that we have captured have spent a couple nights in the pen and have been only fed a little bait. One of the tasks we need to complete today is to head up to the North Sound holding pen with a cooler of small bait chunks for feeding our juvenile wards. I always love getting into the pen with the lemons. Despite their diminutive size, they are perfect replicas of the nine plus foot adults. Watching them swim in their swirling schools manages to mesmerize me every year.

Returning to the lab in the afternoon, we found the away team slowly shaking the sleep out of their eyes. After eating, the main work for the day would be to check the remaining gillnets for holes so that all the nets were repaired as we began the second round of fishing in the North Sound. With a large team working on the nets, they were stitched up in a relatively short time. Other small tasks, like data entry and Q-beam repairs were also addressed. This short break day was productive and the whole team could appreciate a few hours of personal time after dinner. Many individuals watched movies, while others caught up on email, or buried their nose in a book. These simple pleasures really help you relax a little after the challenging schedule of staying up several nights in a row on only a few hours sleep. Everyone is expected to get a good, full night's sleep tonight, and wake up refreshed for the start of fishing again tomorrow night. The thirty sharks we have caught so far are below average. We may either catch quite a few or next to none on the last three nights of the North Sound. Only time will tell...

Tonight we are back out in the lagoon, driving the skiffs up and down the nets for all the hours of darkness. Large storm clouds gather and there is a beautiful natural light show in the clouds for our entertainment. We are lucky though, and the clouds drift right on by Bimini without dousing us with a shower. After the storm passes, the wind dies down and the lagoon gets very still. This make sit very easy to see the bottom of the net and detect any sharks, but all that is observed is meters of empty monofilament. The stillness also means one thing we are fearful of - BUGS. Mosquito is a dirty word around the lab, but a known hurdle to compleing the work in the lagoon. I have never heard of a mangrove swamp not having swarms of mosquitos - if such a place exists then maybe someone will be kind enough to enlighten me as to its location. Everyone has their personal way top defend against bugs, ranging from funky looking mesh jackets, to strange smelling creams and sprays, to the proven and reliable swat method.

The bugs come out in force but after about an hour the winds start to pick up again later, and the numbers of small flying annoyances drops significantly. Despite our high hopes for a large secnd half catch, we manage only three sharks for the night. Two are newborns and the last shark is a recapture from the previous year. This means that our four night total is only thirty-three sharks. It also means that we can probably expect the next two nights to be similarly slow. While a bit dissappointing, we will forge ahead so that we can put in the same amount of sampling effort as in other years. We fish for twelve hours to cover a whole tidal cycle. We gillnet for six twelve hour sets in two different lagoon areas. That means that a total of one hundred and forty-four hours for each net must be completed. We fish with three nets for a grand total of four hundred and thirty-two gillnet hours will be put in by the team. We are one-third finished with the gillnetting, and have so far seen a below average return. Hopefully the Sharkland nursery we will fish next week will bolster our catch a bit.

Night five arrives and the team doggedly prepares its gear and departs for the North Sound. The last two nights will probably be pretty quiet, with few shark catches and long hours staring at empty nets. Since the last couple nights usually prove to be slow, the away team usually tries to switch things up and keep themselves entertained. Team members swap from boat to boat so that the taging boat can get involved in checking the nets. Boat captains relax a little and even give some of the volunteers the chance to drive a gillnet check - a good way to ensure future boat captains. The driving of the skiffs is an acquired skill, incrementally improving with time. The ability to drive closely along the net in wind and current is a big responsibility. The chatter on the radio the last couple nights is always fun, as games and trivia questions are posed for the rest of the team to answer. While there isn't a lot to do in terms of sharks, there is always a story to tell or a laugh to share. In certain respects these can be the best nights out on the boats, as the cameraderie born from these long nights is everlasting. I have many fond memories of being on the boats the last few nights of several PIT censuses. I still stay in touch with many of my boat-mates from previous years.

The stillness is broken in the early hours of the morning. There is a shark in one of the nets. The team instantly is mobilized and switches from lazy campfire story telling mode to full alert. The tagging boat gets all the workup gear together and prepares for the shark's arrival. The little spot of excitement is a refreshing change. The workup goes smoothly and before long the small lemon is cruising around the pen with its cohorts. The tagging boat also gets to feed the baby sharks during the course of the night. It only takes a few days to train the juvenile lemons to associate the splash of bait hitting the water to equate to a meal. Once trained, they hone in like cruise missiles at the sound of the first chunk of barracuda hitting the water. Tonight they are extra frisky, and form a big ball of moving bodies and flapping fins as they swim tight circles to suck down the fish pieces we throw them.

We manage to catch one more shark for the remainder of the night. While the first shark was a newborn, this shark registers a PIT tag when scanned. Add one more recapture from last year to the total. This shark was able to survive the crucial first year of its life, and has a very good chance of making it up to adulthood. As an adult, it may return here to Bimini to drop its pups. Last year's PIT Census showed that sharks originally born here about fourteen years ago returned as mother sharks. This was the first example of sharks returning to their birthplaces to have their own young. It was a very exciting addition to the story of the life history of the lemon shark. Just after dawn, the away team packs up and heads back in to the lab. The home team is waiting for them and starts the tasks of cleaning gear and repairing gillnets. So goes the cycle of work, which facilitates us to discern more about the greater cycles of the lemon shark.

This is it, the last night of the North Sound lagoon and the imminent halfway point to the PIT Census Project. Despite the slow shark catch outlook, the team's spirits are on the rise with the sense of completion that comes with finishing part of the lagoon. We will also be taking three days of "rest" before starting the fishing in the other part of the lagoon. Everyone is looking forward to catching up on sleep and getting a little free time to relax. There are now a grand total of thirty-five sharks in the pen. They swim in a behavior called "fish-milling", which means they form a large swirling circle of little toothy torpedos. Lemon sharks appear to exhibit many forms of social behavior (currently under study by principal investigator Tristan Guttridge). These large fish-mills are artificially created in the confined pen environment, but small groups of three to ten or so sharks can be observed doing the same behavior in the lagoon.

Mother nature saw fit to dampen our spirits a little, as we had only been out for a little while when the skys opened. The rain was light but incessant and everyone was soaked to the core after a little while. These are the nights that we consider "hardcore" as you have to put the work above your own comfort and get the job done. The small sacrifices will pay off in the end. The bright side to some rain and wind is that the bugs stay at home and working without mosquitos buzzing in your ear is always welcome. The summer weather, with thunderstorms passing through the area has arrived. The last night proves to be successful though, as we catch three additional lemons. This includes two more recaptures and one newborn. The final total for the North Sound is thirty-eight sharks. This is a significantly low number (for comparison, last year we caught ninety sharks). The low number of sharks is a bit puzzling and even a bit disturbing. there are several possible explanations, but we will have to wait and see how the Sharkland lagoon goes before we can make any surmises.

While the home team can stay dry in the shelter of the lab, they know how it feels to be in the rain. Every thermos is dug out of the cabinets and extra coffee, tea, and hotr chocolate is prepared. The hot drinks will be a small but well appreciated comfort for the away team during the wet night. The hot drinks and hot food is packed into a large cooler and brought out to the away team in the middle of the night. The "food run" as it is colloquially known around the lab, is a much anticipated highlight of the night for the away team. It is also a chance for a couple of the memebers of the home crew to take a boat ride and get out of the lab. Tonight, the away team is especially happy to see the lights of the food boat, and even more excited by their extra hot drinks. All the boats gather by the main pen and enjoy a communal meal. The net boats sip from their thermos and the contented look on their faces is a big reward for the home team. The wee hours of the morning are a lot more friendly with a hot cup of refreshment to get you through.

The North Sound is in the books, and we have a few days before we start fishing again. This year we are taking three nights off between the different areas of the lagoon. The main reason for this is to avoid the extreme tides when the water will be very low and make working in the shallow lagoon difficult. The location of Sharkland in the main lagoon also means that it has more water pass through it during the changing of tides. This can create strong currents that could be problematic for having our nets set. By skipping the most extreme tides we can reduce this problem as less water moves during average tides. There is a lot to do before we are prepared to fish in Sharkland though. The first step is to release the captured North Sound sharks and take down the holding pens. All the pens then need to be moved down to their locations in Sharkland and be rebuilt. Five pens need to be constructed in total. All the materials - rebar, cinder blocks, and mesh will have to be carried by boat to the south. Once relocated, each pen will have to be erected and perfected so that we can safely place sharks in them. The key to building good pens is to keep the mesh fairly taut so there are no major folds.

When you get folds, sharks could potentially become snagged or even trapped in them. This could stress them out and cause them to expire. The pen building is always overseen by an experienced crew member. First a skeleton of rebar are staked into the sand at a given circumference from a center spot. The mesh is then unrolled and placed around the outside. One side of the door is staked into place and pen building proceeds in one direction. The mesh is streched to the next rebar, which is pulled out and laced through the mesh so there is a lip of mesh on the bottom. The mesh is attached to the inside of the rebar using zip ties. This creates a smooth, continuous surface of mesh on the inside of the pen. The sharks can swim along these barriers, but will not be able to entangle themselves. The bottom lips face outwards and we use cinder blocks to weigh them down and keep them on the bottom. Many times we try to push sediment over the flat mesh to make a seamless bottom edge to the inside of the pen. This is the most crucial area, as the bottom mesh sometimes wants to wrinkle up, and a shark could try to struggle out a small tunnel created this way. The pens are checked via snorkel and any modifications are made until they are secure and safe for the sharks.

The building of the pens takes a lot of time, but we manage to get all five pens done. Each net location has a small holding pen built near it. That way if the tide is low and the skiffs can not easily transport the sharks directly to the tagging boat, they can simply drop them in the local holding pen. The main pen is where the worked up sharks are placed to be held until the fishing in that area of the lagoon is finished. Usually that is sufficient, but this year we have an additional pen adjacent to the main pen to place sharks for eversions. As the shark is worked up, its belly is felt to determine if has recently fed. In the case of a full stomach, it is dumped into the eversion pen. A crew then comes up the next day to evert the sharks and see what they ate. If anything includes yellowfin mojarra remains, then it is saved for a genetics project currently be conducted by Dr. Demian Chapman. The eversion pen is bigger than one of the net holding pens but still much smaller than the large pen. The large pen is definitely akin to the main stage at a music festival. That is where you want to be to see the most action. With all five pens up, we are prepared to set nets again when the tides are more favorable. We should be able to get a lot more accomplished in the next two days before our fishing schedule resumes.

Today is a rest day, though we have lots of work to do. The biggest thing is that Doc and film crew will be arriving on Monday, so we will be having a cleaning day. A cleaning day at the lab means that everything, and I mean everything must be thoroughly cleaned. There is a three page list of items to be completed to make the lab look good inside and out. The yard, trucks, boats, kitchen, bathrooms, and lab all have to be gone over with a fine pick comb and made to look their best. The cleaning day is also a chance to do some inventories and assessments of food and lab equipment. The lab is a flurry of activity as everyone picks a few items on the list and get to work. Brooms, brushes, rags, and wipes fly everywhere until not a spot is left untouched. Outside, the roar of the lawnmower can be heard, along with the swoosh and clink of the machete trimming tree branches. The trucks get good washes and some buffing, and oil and other fluids are topped off. The boats get a comprehensive clean, lines are organized, and the engine cowlings are waxed to a high shine.

Inside the lab, Kat is orchestrating the multitude of activities. The smell of bleach and other various cleaners wafts through the kitchen and lab room. Every surface is scrubbed and disinfected. Cabinets and drawers are emptied, sorted, and organized. Dust and dirt is discovered hiding in strange corners and banished from the lab. It is really impressive to see the transformation. During PIT, with the hectic schedule, the lab tends to become a little organized. It is a evident difference when everything is in its labelled place and all lined up and organized. It takes a good portion of the day, but item by item the list is checked off. The lab looks neat and clean, just the way Doc likes it. Besides overseeing the cleaning, Kat also is in and out of the kitchen making sure we will get a hearty lunch. She is the real backbone of the lab, and keeps everyone going. Her long hours of hard work are deeply appreciated by everyone who comes to the lab. With the lab tidy, we have one last task ahead. The late afternoon is spent preparing and double-checking all of our long-line equipment. We will be setting some lines tomorrow and hopefully catching some big sharks. It is a thrill to see the big boy and girls and a nice reward for all the hard work put in during PIT.