Archive for August, 2010

Joanna Carey is conducting her silica research at Babson Creek. Don't let the marsh's seemingly lack of fine sand particles fool you! The marsh is full of silica (L.Weisenfluh/ July 2010).

Its that time of the year again–summer time, or as I like to call it–vacation time (booyah!). After weeks of careful planning, you manage to take a few weeks off from work and head to your favorite lake house for some well needed vacation time. However, upon arrival to your lake house, you gape in horror as you see that your beloved vacationing spot has turned a murky green. That’s right–no swimming for you. In an outrage, you demand to know why your beloved vacation spot has turned a ghastly green. The answer lies in a phenomena that is known as eutrophication.

Eutrophication is the result of nutrient run-off from human industries, including fertilizer from farming activities. After fertilizing the plants, the fertilizer will find itself in some nearby lake or pond. And because these nutrients function as a food source for phytoplankton, phytoplankton will dramatically increase in numbers,  thus turning the body of water into an unhealthy green color. While the phytoplankton is flourishing, other organisms will perish due to the lack of oxygen and sunlight.

When I personally think of nutrient run-off, I have been automatically trained to relate it to nitrogen and phosphorus (the most widely studied nutrients when it comes to eutrophication). But thinking about eutrophication just in terms of nitrogen and phosphorus completely ignores the fundamentals of ecology–that is, that everything is connected. In fact, nitrogen and phosphorus are just tiny parts of the ecological equation, yet receive most of the scientific attention. Nitrogen and phosphorus must be interacting with other chemicals that receive far less scientific attention. How about… silica, or instance?

Now that's a sandy beach! A shot from back home, Point Reyes, California (L. Weisenfluh/ August 2009)

Most people know silica for its presence on beaches in the form of small quartz pieces–sand. But silica isn’t just found on beaches, but other bodies of water, such as marshes. In fact, the presence or absence of silica  is very influential in an ecosystem. Silica provides organisms with protection from desiccation and predation through its hardening capabilities. Diatoms (phytoplankton algae) use silica to maintain their cell walls; diatoms will actually bloom according to the availability of silica. Under normal circumstances, silica will be found in a 1:1 ratio with nitrogen in an ecosystem, meaning that, under this ratio both diatoms and nitrogen-feeding phytoplankton will live harmoniously in balance (relatively speaking, of course). However, when the silica to nitrogen ratio is less than one, silica concentrations will be low and not able to sustain a high diatom population, thus allowing non-silica limited algae (i.e. nitrogen-limited algae) to bloom and out compete diatoms. This results in rather nasty business for the environment, including eutrophication and red tides.

Because silica has this important regulatory role in an ecosystem, scientists are very interested in learning more about silica, hoping that it might give them some insight pertaining to eutrophication. However, we must address another concern before we can even venture to explore these implications: we have very little idea as to how silica travels through an ecosystem. Therefore, before we can even start to hash out implications of these correlations, we must determine something called a silica budget.

No, I am not talking about money. Rather, I am using the term “budget” in a purely ecological sense. When an ecological talks about a “budget”, he/she is referring to an attempt to quantify the distribution of particular elements (silica, in this case) and how it is transported throughout an ecosystem. Ecologists make budgets for all types of nutrients—nitrogen, phosphorus—and yes, even silica. Thing is, there haven’t been any attempts to make a silica budget in Northern America. That is…until now. Joanna Carey, a PhD. Candidate at Boston University is attempting to create a silica budget for a coastal wetland within Acadia National Park (Babson Creek, anyone?), with the hopes that this information can ultimately be used to infer how silica affects the biogeochemistry of an ecosystem. And just how is this accomplished? Very carefully…

Researchers take silica measurements out of the PVC contained marsh samples. Before using these PVC pipes, researchers were measuring silica over a large marsh flume. However, water was moving too fast over the flume for an accurate measurement, therefore requiring researchers to use PVC pipes as a smaller flume enclosure (L.Weisenfluh/July 2010).

In her project, she is measuring two different types of silica: dissolved silica and particulate silica. Now, before the technicality of these terms chases you away, let me explain their significances: dissolved silica is silica that has yet to be used by organisms, and therefore indicates the amount of silica that is available for biological processes. Particulate silica (i.e. biogenic silica) is silica that has been hydrated (contains water), as a result of plankton biological processes. It can be found and measured in sediment and vegetation.

One can use these particulate and dissolved silica measurements to determine a silica budget. Both of these measurements are taken as water flows into large PVC tubes (a small replica of the larger marsh) under dark conditions (as to measure silica fluxes under non-photosynthetic processes, such as respiration). Researchers sample the water within these tubes for silica, phosphorus and nitrogen concentrations every 75 minutes for 5 hours.

Joanna Carey collects vegetation samples from the marsh by giving it a "haircut". By analyzing this vegetation sample back at the lab, she will be able to determine the amount of particulate silica found inside the vegetation.

The particulate silica can also be measured by examining silica concentrations in sediment and vegetation. This is done by taking sediment cores (you essentially core the marsh’s sediment, and then analyze this sediment for silica). Once the sediment is cored and extracted for measurement, researchers insert another tube into the marsh–a tube with dialysis membranes lining the outside edges of the tube. Dialysis membranes allow the salt water of the marsh to equilibrate with the water inside the dialysis tubes. Once the two environments have equilibrated their ion concentrations, researchers collect the dialysis tubes and analyze the samples to determine silica, nitrogen and phosphorus values. Researchers also take vegetation samples (of two widespread vegetation types—Spartina patens and Spartina alterniflora) and analyze their silica content back at the lab.

We shall see what the results of her research dictate… Ms. Carey is still in the process of carrying out her field work. But until then, don’t take that sand beneath your toes for granted–its small and unseemly presence is a part of something much greater and more important… rather an entire ecosystem.

Read Full Post »

This foggy bog is one of the many randomly selected sites that Lisa Smith has placed phototraps. Don't let the vegetation fool you; you will sink into the murky water if you step off of the plank (L.Weisenfluh/July 2010).

Steady, steady. Be graceful—like a tiger. You can do that, right? Heh—who are you kidding? You have the grace of an elephant, remember? Add it to a dose of morning grogginess, and boy, you’ve got quite a show. After all, one momentary lapse could result in a cold, muddy “Good morning!” because I wasn’t scaling an ordinary wooden beam—there be boggy waters below!

No, I hadn’t gone stir-crazy. And no—I hadn’t mistakenly entered these mysterious waters. In fact—quite the contrary. As a science communication intern, I had the opportunity to go out into the field with a graduate student from the University of Maryland at Frostberg, Lisa Smith—an opportunity which resulted in exploring a watery bog at early hours of the morning. She is currently conducting research on the wildlife species composition on the Schoodic Peninsula as a part of her Master’s Thesis. Her project is a part of a much larger scheme: researchers are hoping to install a wildlife corridor throughout the Schoodic Peninsula.

Why are such corridors needed? Habitats have become fragmented with the increased flux of people coming through the area. Roads have been built. Properties have been developed. The result is a bleak picture for wildlife: isolated in smaller habitats, they have fewer resources available—whatever it may be, whether food, mates, or territory. As a result, ecosystem health diminishes. Conservationists hope to reverse this process by putting the fragmented habitats back together through small pieces of land that re-connect the fragmented habitats—wildlife corridors.

But where to place them? That’s the tricky part and where Lisa Smith’s research comes in. She hopes to locate where and what types of animals are located throughout the Schoodic Peninsula so that wildlife corridors can be assigned appropriately. Lisa Smith randomly picked out sites (like the watery bog) to place phototraps. Phototraps are cameras that take pictures when triggered by motion or heat. In other words, these cameras will capture all instances of wildlife passing by it—everything from raccoons, bears, or porcupines. And what attracts the animals to the phototrap sites? Some good ol’ fashioned lures, of course!

But before re-setting the trap with numerous lures, the cameras need to be checked to see if they are working. After safely making it across the bog (and yes—I miraculously managed to avoid plunging to the watery depths below), Lisa Smith approaches the phototrap, opens it up, and checks for photographs. No photos on this one. The meat is gone….but where are the photos of the creature that took the meat? Is it working? She decides to re-place the camera. Next off, she needs to re-set the site with a variety of scents and bait. Mmmmm—buffet time.

Lisa Smith administers cat nip oil to the hanging feather scent lure (L.Weisenfluh/July 2010).

As Lisa Smith opens her red case of lures, a peculiar scent fills the air—a strange combination of urine, meat, and skunk. There are several types of lures that she employs to draw animals to the phototraps. First, she re-administers the hanging trap, comprised of a film canister and feather. The film canister is filled with a mixture of Vaseline and skunk spray. She sprays cat nip oil on the feather below. On the site below, she fills two old empty bullet castings with a variety of things, including beaver castor (a secretion used for scent marking). Last, but not least—a small suet of meat. And…bon appetite! Aren’t you hungry now? While the menu may not sound appetizing to the normal human being, these lures have been specifically designed to attract carnivores—animals that will be afftected by wildlife corridors through their large ranges.

After replacing the dysfunctional phototrap with a functional phototraph, we head off to the next site. Lisa Smith spends her entire day driving from site to site, re-administering lures and setting up new traps. Out of 60 traps, 50 appear to be working, leaving her with 50 lure sites throughout the Schoodic Peninsula. She leaves the traps out for ten days at a time, re-luring and checking each site on day five of each ten day period. Lisa Smith wishes to cycle these phototraps through three to four cycles of these ten day periods, hopefully giving her lots of wildlife sightings (and therefore lots of data). Personally, I am excited to see what her results may bring, and more specifically, how they will help implement successful wildlife corridors. Until then, take caution to avoid any particularly odd smelling areas while exploring the lovely Schoodic Peninsula; you could be on camera!

Read Full Post »

Great Brewster Island through the fog. (CLT, 8/5/10)

Our last trip of the season took place in the foggy haze last Thursday.  We began our day with a stop by the Least Tern colony on Lovells Island.  We saw only 4 adults and 1 fledging in the area, but Bob Kelley reported approximately 20 adults and 10 fledglings (or chicks near fledging) on August 1st, so it looks like their second nesting effort was successful.

We were prevented for reaching Snake by an incoming LNG tanker – AGAIN!  In my eight years doing research in the islands, I have crossed paths with only 3 LNG tankers, and 2 of them happened to fall on our last two trips!  We hope the Snake oystercatchers were successful!

On a quick loop around the Outer Islands (excluding Green & the Graves) we observed numerous adult eiders and several females with still-recognizable chicks (a total of 30), so even the late nesters seem to be doing well this year.  We also encountered a pair of American Oystercatchers (AMOY) still present on Middle Brewster.  We did not see any chicks, but they still seemed to be defending the western end of the island where we’ve seen them before.  We also had 2 AMOY feeding on Shag Rocks.  We observed one immature GRCO on Little Calf, 2 gray seals and 4 Spotted Sandpipers (SPSA) feeding on Little Calf, Outer Brewster, Middle Brewster, and Shag Rocks.  Shorebird migration is well underway and Ruddy Turnstones were also observed on Outer Brewster and Shag Rocks.

We ended the day on Rainsford where we divided into 2 teams and scoured the island for AMOY and SPSA.  A pair of AMOY remain on ‘Piggery End’ near the landing beach, but no chicks were observed.  A second pair of AMOY were observed on the northeast end of the island, accompanied by one fledgling.  Two spotted sandpipers were all we could turn up on Rainsford, so it seems probable that their nesting effort has concluded for the season (without us finding a nest, I might add….)

While hard-working volunteers did all the active searching on Rainsford, I set up a dummy tern colony on the northwest end of Rainsford where Least Terns have nested historically.  I had earlier painted 37 wooden eggs to resemble least tern eggs (to the best of my limited artistic ability).  I arranged these eggs into 20 nests in what I hoped was a realistic colony construction.  I then asked my 5 intrepid volunteers to approach the ‘colony’ site and conduct a nest survey using the same methods we’ve been using all season (see http://science.nature.nps.gov/im/units/NETN/monitor/birds/cbbirds.cfm for more on monitoring protocols).  On the first pass, they turned up 20 out of 25 nests, for a detection rate of 80%.  This information shines new light on our efforts at the Lovells colony – is it possible that there were actually 44 nests at Lovells this year, instead of the 35 we found there???

Thanks to all the hard-working volunteers who participated in our field season this year!  I can’t tell you how much I appreciate their hard work and patience – in addition to their stimulating questions and good humor.  They have all contributed immensely to improving this project each year. (And made it a lot of fun for me!)  Till next season – Carol

Read Full Post »

Welcome to your new tropical abode, Gilligan. Sure, the scenery's great, but the potential wife factor is extremely lacking (L. Weisenfluh, January 2008)

Ecologically, isolation can be detrimental to a habitat. Think about it in terms of your own relocation. You move to, say, some newly discovered island off the coast of Costa Rica.

What biological processes do you need to conduct in order to live and perpetuate your genes? You need to eat. Okay, so learn to hunt wild boars (mmmm… bacon). But what happens if you over-hunt the local boar population and cannot find anything else to eat (yes, everything else is poisonous, for the sake of this argument)?

Better yet, what happens when you wish to perpetuate your fitness? Even if you have brought along your significant other, who will your children mate with? Don’t even think about inbreeding–this will seriously decrease your genetic fitness by revealing those nasty little recessive deleterious traits.

A classic anthropogenic barrier--a road (G. Weisenfluh, April 2008)

Now, make this less personal, and think about it in terms of animal populations, animal populations that have been isolated (or fragmented) due to ecological processes, such as fires or human activities (roads, cities, and so on). How do we revive ecosystems that have been fragmented? You guessed it: by putting them back together.

That’s exactly what Dr. Robert Brooks of Pennsylvania State University hopes to do in downeast Maine from Schoodic Point to Schoodic Mountain. The region in between is ecologically diverse, with a wide range of habitats– everything from coastal to terrestrial to freshwater. By connecting these habitats in the form of a wildlife corridor, animals will have more habitat to live in and move through safely–this means more movement, more mixing, more food options, mating opportunities, etc., etc., thus a healthier population.

But in order to establish this wildlife corridor, scientists must first prove that these fragmented habitats are worth connecting–that is, that they contain species that need the wildlife corridor to thrive. Scientists are currently conducting research to survey for such wildlife. This inventory and monitoring work involves setting, baiting, and checking phototraps which attract mammals and then snap their portrait when they pass in front of camera (the animal’s body heat and movement triggers the camera). After surveying the animal populations in the Schoodic area, the research team will be able to better determine whether the wildlife corridor will help reduce fragmentation and therefore improve the health of the area’s ecosystems.

Read Full Post »