"Coastal Conversations" tackles the subject of Ocean Acidification

Maine's independent community radio station, WERU 89.9 FM, just added another great new program for listeners: Coastal Conversations, a new science and conservation program hosted by Maine Sea Grant's Natalie Springuel, will air on the 4th Friday of every month from 10-11am. Springuel's topic on January 23rd was ocean acidification, and she kicked off the conversation with Joe Salisbury of University of New Hampshire and Bill Mook of Mook Sea Farm, who helped listeners understand the chemistry behind ocean acidification. Here is a brief synopsis:

Simply put, ocean acidification is the result of lowered pH in the oceans (ocean water is usually 8 on the pH scale which ranges from 0-14). Unfortunately, the pH scale can be a bit challenging to interpret: it is a logarithmic scale that represents concentrations of hydrogen ions, so lower pH (7 is neutral) corresponds to increasing acidity. There are three main processes that tend to lower pH levels in the ocean (making the ocean more acidic):

1.  When CO2 from the atmosphere dissolves into the surface ocean. Normally, this isn't a huge problem as the ocean has the capacity to take in some atmospheric CO2, but what we are facing is an excess of atmospheric CO2 which is only increasing. This is mostly a consequence of human activities like burning fossil fuels. 
2. Increased freshwater runoff into the ocean. According to the National Weather Service, Maine has seen a 73% increase in the top 1% of storm events over the last century. This means that big storm events (which maybe happened only once every five years in the past) are becoming more frequent. When large storms happen, they literally flood existing municipal infrastructure, which often means that storm drains, dams, and sewers overflow, causing a huge influx of freshwater into the oceans over a relatively short amount of time. Freshwater typically has a pH of 5, so this influx leads to lower pH levels in the coastal zone.
3. Storm events don't just dump freshwater into the oceans, but also often bring along nitrogen and other nutrients. This one is a bit tricky, because nutrients don't directly increase the acidity of the ocean, but eutrophication (a fancy way of saying adding nutrients) starts a chain of events which ultimately leads to lower pH. Coastal zone productivity is usually limited by nitrogen availability. When nitrogen is added to the ocean (some sources include agricultural runoff of high-nitrogen fertilizer or from sewage runoff), micro algae get really excited and start photosynthesizing like crazy. An algal bloom forms, and then, when the photosynthesizers die off and sink, they in turn are consumed by mircoorganisms that also consume oxygen and respire CO2 creating hypoxic (low oxygen) zones and low pH zones.

Lobster is just one of many important commercial shellfish in Maine that is susceptible to ocean acidification.

So these processes lower ocean pH...what's the big deal? And which processes are having the biggest impact? We don't know all of these answers yet, but Dr. Salisbury and other scientists are documenting the seasonality of CO2 and pH levels in the surface ocean to see how much phytoplankton blooms, freshwater runoff, upwelling, and horizontal mixing are contributing to changes in pH compared to atmospheric CO2 emissions. We do know that lower pH impacts a lot of organisms in the ocean that we commercially harvest. Lower pH drops the concentration of carbonate ions in the ocean which is an important part of the compound calcium carbonate--a crucial ingredient in creating the shells of commercial shellfish including lobsters, oysters, scallops, and clams. According to Joe Salisbury, shellfish aren't the only critters that may be impacted. Fish can also face reproductive and olfactory (sense of smell) stress in lower pH environments, and low pH can even change how sound travels through water, which may impact how whales and other marine mammals communicate using vocalizations underwater.

As an oyster farmer, Bill Mook has seen first-hand what lower ocean pH can do to his larval oysters. Larval shellfish are much more vulnerable to ocean acidification compared to their adult companions. According to Mook, the calcium carbonate form that larvae use in their shells is aragonite, which is much more soluble (easily dissolved) in lower pH conditions. Larval oysters typically develop from fertilized eggs in 24 hours and live as swimming larvae from 14-16 days. Mook has noticed that since 2006, there have been more incidents at the hatchery where fertilized eggs do not convert to larvae and just die, or the larvae grow much more slowly, stop feeding, and generally take longer to go through metamorphosis. These events are often linked to runoff events from rain storms, and may be the canary in the coal mine for what the future may look like for shellfish.

So what is Maine and the scientific community doing about it ocean acidification? Damian Brady of Darling Marine Center, UMaine, and Esperanza Stancioff of University of Maine Cooperative Extension are great examples of other researchers and educators that are trying to learn more and educate people about the problem. Damian Brady works with numerical models to try to learn more about how changes in temperature, precipitation events, runoff, and land-use practices can mitigate some of the conditions we are seeing in the ocean. The state of Maine has also been one of the first states to mobilize forums, conferences, and meetings focused on ocean acidification, and there are several formalized networks and organizations that are also working to learn more about ocean acidification. Two that were mentioned during Coastal Conversations are The Northeast Coastal Acidification Network (NECAN) and The Ocean Acidification Commission (OAC). NECAN has been working to compile data and research around ocean acidification including hosting a series of webinars and a 2-day "state of the science" workshop. The OAC was formed less than a year ago by the Maine legislature to compile information about existing and potential impacts of ocean acidification on commercial species. Their goals involved identifying existing research and potential monitoring, mitigation, and education opportunities to continue to engage researchers, industry members, and the public in this issue. The OAC recently released a report (a link to the draft is here) outlining the following recommendations: 

1. Increase Maine's capacity to monitor the impacts of ocean acidification
2. Reduce CO2 emissions in Maine, and encourage new innovative technology to help make these reductions possible
3. Reduce nutrient and freshwater runoff
4. Mitigate, remediate, and adapt (for example, preserve macro algae (seaweed) areas, and use shells to buffer mudflats)
5. Educate the public about this issue
6. Sustain these research and mitigation efforts in Maine in the form an ocean acidification council to see this process into the future

If ocean acidification is a topic that interests you as a student, researcher, or citizen, then get involved! There are many research questions yet to be asked and explored, and opportunities to help Maine move forward to mitigate our impact on our oceans. The state of Maine currently doesn't require schedule maintenance of homeowner septic systems, there is not yet a citizen science ocean acidification monitoring network, the body of published scientific literature on ocean acidification is less than 10 years old, and there are still opportunities to develop curriculum around ocean acidification and share what you know with others! The time is now and you can make a difference! 

At the very least, be sure to stay informed by reading up on marine conservation issues and by tuning in every 4th Friday of the month to Coastal Conversations on WERU 89.9 FM or live-stream from weru.org. 

Understanding Green Crabs in Maine

Yesterday, December 10, 2014, I had the opportunity to travel down to Castine, Maine, to attend an Eastern Maine Skippers Program cohort gathering hosted at Maine Maritime Academy-- the first time the skippers have connected as a full group since their kickoff event on Hurricane Island. The focus of this day was to give students a chance to explore and discuss some of the more nuanced facets of "the green crab problem, " and start to explore project ideas that they can research or test this school year.  A variety of experts attended to share their expertise from the perspective of marketing, management, harvesting, and mitigation and ecology, including Les White, biologist at the Maine Department of Marine Resources (DMR), Dr. Brian Beal, professor of Marine Ecology at University of Maine at Machias, and Mark King from the Department of Environmental Protection. 

The session I sat in on was run by Dr. Brian Beal on Understanding green crab population dynamics and their effects of cultured and wild populations of soft shell clams. Dr. Beal is the director of research at the Downeast Institute on Great Wass Island, and has worked extensively with clams in a hatchery setting, but also expanded his work to look at the impacts green crabs have on clam populations.

The first part of his talk was focused on understanding the life history of green crabs (Carcinus maenas). It is important to have this background when brainstorming potential solutions to "the green crab problem," because the way that green crabs reproduce, the habitat they prefer, and their tolerance to a wide range of temperature and salinity conditions explain why they have been so successful at invading Maine's coastline, and can give us clues on the best strategies to mitigate (reduce or manage) green crabs to help maintain the coastal systems and commercial fisheries they impact. 

Green crabs originated from Ireland or England, and have since spread to different parts of the world including Japan, Australia, Sough Africa, and Patagonia. The first green crab sighting in Maine was in 1905 in Casco Bay, and, Dr. Beal noted that from that point they slowly spread north reaching Lubec in 1951. The net flow of Maine's tides is south, which means that green crabs likely traveled in ships ballast (the same strategy that brought them over from Europe in the first place) to spread up to northern Maine rather than migrating against the tides.

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A female green crab carrying a large mass of eggs (orange), secured to her telson with an excreted glue-like substance

Dr. Beal describes green crabs as a "consummate invader of new ecosystems," because several aspects of their life history make them well-suited to quickly expand their populations when they reach a new area. Green crabs are highly fecund, which means that they produce a TON of eggs, and the number of eggs female crabs can produce increases exponentially as they get larger (a 2-inch carapace length female can hold an estimated 165,000 eggs). Females protect and carry their eggs under their telson ("tail" flap) until the eggs hatch into planktonic (floating) larvae.  Larvae are then carried long distances by the wind, tide, and ocean currents-- so by the time they settle out of the water column onto the ocean floor (after 50-80 days of floating) one female's offspring may have dispersed to locations miles away. Another aspect of their life history that makes green crabs really resilient is that the larvae can survive in a wide range of temperatures (a range from 8-25°C or 46.4-77°F) and salinities (10-30 ppt). Adult crabs can survive even more drastic temperature and salinity ranges, and researchers have seen green crabs survive completely out of water for nearly 10 days in typical Maine summer conditions. Finally, green crabs aren't picky: they thrive in mud, cobble, sandy, and rocky intertidal and sub-tidal environments, and they eat just about anything--clams, mussels, lobsters, marine worms, cord grass, and eel grass--so  they can be successful nearly anywhere along Maine's coastline.

One parameter that does seem to keep green crab populations in check is really cold temperatures (at least -1°C or 30.2°F) that are sustained over several winter months. If the average minimum monthly temperature increases by just a few degrees (2°C or 5°F) a large portion of the population survives the winter and continues to grow and reproduce. This type of change happened between 1940 and 1950 (which caused populations of green crabs to explode), and again on a smaller scale between winter conditions in 2013 to 2014. Dr. Beal's initial green crab data collected during his research in 2013 shows how much difference one cold winter can make: his team caught an average of 10 pounds of green crabs per research trap in 2013, and a pound represented an average of 12 crabs. In 2014, he only caught 1-1.5 pounds of crabs per trap, and the crabs caught were much smaller--it could take up to 56 crabs to make up a pound. Maine experienced a particularly warm winter in 2012-2013, allowing the green crab population to thrive and grow, but then a cold winter in 2013-2014 killed back a lot of the adult crabs, leaving Dr. Beal and his researchers with a catch of mostly small young crabs in 2014.

As we continue to see global changes in water temperatures (the Gulf of Maine Research Institute found that the Gulf of Maine is warming 99% faster than the rest of the worlds oceans), it appears that this "green crab problem" isn't going to just go away. This is where our Eastern Maine Skippers come into the picture. They are working hard this year to develop projects to figure out creative ways to mitigate the impacts of green crabs in Maine. Stay tuned!

Ocean Advocacy: From the Bow Seat

We are excited to announce that our new partner, From the Bow Seat, has recently launched their fourth ocean advocacy competition for 2015 with the theme "Our Oceans, Our Plastic." If you wish to submit a compelling work of art, a poem, a written work, or a film about plastic pollution in the ocean we encourage you to get your voice or visual out there before June 15, 2015! The contest is open to middle and high school students, read more about the submission guidelines here! Cash prizes will be awarded to 1st, 2nd, 3rd place, and honorable mention winners in each category. There are also three Teacher Recognition awards, and the top student prize in each category will receive $1,500 for themselves and $1,500 for their school.

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Ocean Acidification Workshop

Participants listen to opening remarks.

On October 7, 2014, I had the opportunity to attend a workshop co-hosted by the Island Institute and the Natural Resources Defense Council focused on "Increasing Community Resilience to Ocean Acidification in Maine: Analyzing and Responding to the Economic, Cultural, and Social Impacts." This event is part of broader efforts underway to understand and address ocean acidification effects in Maine. The Maine Ocean Acidification Commission, a 16-member panel, was established by the Legislature in early summer 2014 to synthesize our current understanding of the issue, its implications for Maine, and identify actions that can be taken to increase our knowledge base about ocean acidification, its effects, and options for remediation, adaptation, and mitigation. The Commission held it's first meeting on the state of ocean acidification science at the Darling Marine Center in August 2014. The October workshop focused on the human and community dimension of the ocean acidification issue.

The speaker lineup started with the mechanics of the acidification process and implications for marine species in response to changes in ocean chemistry. The next set of speakers focused on how communities can define vulnerability, resilience, and identify threats to coastal economic sectors such as fisheries or tourism and biodiversity. Once the morning session wrapped up, we broke into small groups to brainstorm the aspects of our coastal communities that we value and would like to maintain as well as indicators and data sources to measure those values. 

The afternoon speakers provided an overview on solutions, both regulatory and non-regulatory that have been implemented elsewhere to address ocean acidification. For example, local mitigation of ocean acidification is possible through certain measures. Since nutrients are known to increase the rate of ocean acidification, enforcement of regulations meant to control point and non-point pollution sources can reduce nutrient runoff thus eliminating a contributing factor to the acidification process. The break-out groups were tasked with developing strategies to implement in Maine. It was reassuring to see people from different sectors - nonprofit, government, industry - coming together to tackle a very serious issue for Maine. The work done throughout the day will be summarized in a report. We will plan to share the final products once they have been made available... stay tuned!

The Ferns of Hurricane Island

Post by Chloe Tremper, Science and Education Intern

If you find yourself hiking around Hurricane Island's trail system and come across a fern, take a closer look! Can you identify it? Here are different types of ferns we have found this summer. It may help to check out this helpful diagram showing fern anatomy before reading below.

Mountain Wood Fern Dryopteris campyloptera (Kunze) Clarkson.

Sori of the Mountain Wood Fern

Mountain Wood Fern

Mountain wood fern is one of, if not the most abundant fern species on Hurricane Island as it can be seen on nearly every part of the island. These ferns inhabit cool forests throughout New England, though typically are only found on higher elevations in more southern states, hence the name “mountain” wood fern.  Its thrice-pinnate leaf blade, pale green kidney-shaped sori (the little dots on the underside of the main fern blade), brown scales on the leaf stalk, and the veins, which do not reach the edge of the leaf blade, help easily identify this species. Fun Fern Fact: Native Americans used a tea of the leaves to treat stomachaches and used the rhizomes for food.

Rock Polypody Polypodium virginianum L.

Rock Polypody

Rock polypody is another common fern on Hurricane, however you have to know where to look.  Rock polypody often grows directly on rock or on thin soil over rocky cliffs and boulders. We’ve found it growing all over many of the granite rock outcrops within the shade of the spruces and firs here on the island. The blade of rock polypody is once-pinnate and lobed with large, circular sori that tend to be brown in color.  If you look closely at the blade of rock polypody, it almost looks like the pinna are all connected and smoothly zig-zagging back and forth. Fun Fern Fact: It was widely used by Native Americans as a medicinal herb to treat stomachaches, colds, coughs, and other ailments.  

Cinnamon Fern Osmundastrum cinnamomeum (L.) C. Presl

Cinnamon Fern

Cinnamon fern is abundant along trails mostly on the northern half of Hurricane Island, and these ferns are typically found along water edges and within forests.  Cinnamon fern is a large fern that grows in rounded clumps with fertile fronds emerging from the center.  Unlike mountain wood fern and rock polypody, which have spores on the undersides of their pinna, the spores of cinnamon fern are all found within modified leaflets on individual fertile fronds which look very different from the sterile fronds.  The sterile fronds of cinnamon fern are twice-pinnate and can grow to be over three feet in length and the fertile fronds are erect with cinnamon colored sporangia covering the top of the stalk. Fern Fun Fact: Cinnamon fern fiddleheads are mildly toxic and are often mistaken for ostrich fern fiddleheads, which are commonly collected for food in the spring. Careful what you harvest!

Sensitive Fern Onoclea sensibilis L.

Sensitive Fern

Sensitive fern is fairly abundant on Hurricane Island, especially in poorly drained areas open areas as sensitive ferns are indicators of wet sites and are one of a few ferns that are sun-tolerant.  The blade is once-pinnate with slightly lobed margins on the pinna and a light yellow-green color.  Like cinnamon fern, sensitive ferns have fertile fronds that look like rows of black capsules along the top of an erect stalk growing along with the sterile fronds. Fern Fun Fact:  Sensitive fern received its name because the sterile fronds are very susceptible, or sensitive, to frost damage.

Interrupted Fern Osmunda claytoniana L.

Interrupted Fern

Interrupted fern is a very common fern found throughout New England, however we have only found it one location on Hurricane Island so it’s a rare one for us.  They are generally found in forests and along water edges.  The leaf blade is twice-pinnate and many fronds have distinct interruptions at the center of the frond caused by fertile pinnae. The fertile pinnae are generally chestnut-brown to black in color and close to the stalk.  Fern Fun Fact: Interrupted fern has the oldest known fossil record of any living fern in the world, it's been around for 200 million years!

Royal Fern Osmunda regalis L.

Royal Fern

Royal fern is a species found commonly around the world, however we’ve only found it in one location on Hurricane so it gets treated like royalty here! Royal ferns are often found by water and within forests.  The leaf blades of the sterile fronds are twice pinnate with a gap between each pinna.  The fertile fronds rise above the sterile fronds and are somewhat crown shaped, thus the name royal fern. Fern Fun Fact: Royal fern is the largest fern found in North America and the young fiddleheads are edible.

Whew! That's all the ferns we've found for now, but stay tuned, and see if you can find any of these ferns growing around your own home or neighborhood! I recommend A Field Guide to Ferns and Their Related Families: Northeastern and Central North America (A Peterson field guide) if you are looking to become a fern expert :) Happy fern finding!