Tuesday, 29 October 2013

The bigger picture

Our next leg from Bermuda will be about 900 miles and that could take us 9 days.  We carry only enough fuel for about 3 days.   So studying the wind becomes central to our travel plans.  We’ve been doing this and today looks like our day to move to St. Maarten.

While I do not expect anyone to be waiting for the next installment of my blog, I thought I’d take this opportunity to describe a bit of the bigger picture…..

So Why Do This Research?

Science requires you attend to details but sometimes it is good to step back and consider the bigger picture.  In case the science interests you, read on….

Science of the bigger picture
We live in the Anthropocene.  This is the most recent period of significant biological change.  Paleontologists have names for each period when life on Earth changes. Animals with shells and hard parts appeared over 500 million years ago during a period called the Cambrian.  Dinosaurs ruled land during the Triassic, Jurassic and Cretaceous periods of the Mesozoic Era.  More recently, in the Cenozoic Era of the Eocene period, modern reef fishes evolved.  During the Pleistocene glaciers covered the poles and during the Holocene, humans evolved.  The Anthropocene describes the period when the biosphere was clearly affected by human activity.

There is no place on Earth where human presence cannot be detected.  Some impacts are conspicuous such as forest clear-cutting but others are subtle such as global warming and ocean acidification of our world.  The scale of the climate and atmospheric effects is huge – in some ways it is global.  This can have profound effects on lots of critters but none are more affected than coral reefs.  For example, when ocean temperatures coral reef exceeds its average summer temperature by more than about 2 degrees C, corals bleach.  Coral bleaching occurs when tiny, but useful, algae that live within the corals are expelled and corals bleach white.

Bleached brain corals (right side of left photo is not bleached). Bonaire 
Bleached star coral in Bonaire 2010
Another bleached brain coral from Bonaire 2010
Most climate scientists have concluded that the burning of fossil fuels creates a greenhouse condition in which sunlight turned into heat when it strikes Earth, becomes trapped in this greenhouse.  Carbon dioxide also readily reacts with water creating carbonic acid.  This resulted in the acidification of the world’s oceans.

Plants and animals that create limestone skeletons such as lobsters, sea urchins and coral, invest metabolic energy to calcify.  With ocean acidification, the cost of doing the business of calcification has gone up.  Many reef scientists fear that thermal-stress of global warming and ocean acidification have created a ‘double whammy’ that may have serious synergistically negative impacts on coral reefs.

Getting from what we know, to what we don’t know
Reef corals have declined in abundance over the past half-century (at least).  Coral reefs as with most ecosystems are named for their dominant organism, reef corals.  Since reef corals are declining in abundance, coral reef ecosystems are threatened.  On many reefs, as corals decline, seaweed increases in abundance.  Given that in the 1970s seaweed was rare throughout the Caribbean, the trend is clear but what drives this trend is hotly debated. 

Coral reefs in Jamaica (Discovery Bay) shifting to seaweed reefs between 1978 and 1988
Top two and bottom two photos were taken at exactly the same locations.

Could climate change and ocean acidification have caused the decline in coral reefs?  Perhaps.... but there are other, non-mutually exclusive ideas as well.  Some scientists argue instead that the increase in seaweed is due to nutrient increases that stimulate their growth.  Seaweed can smother and even poison coral so that’s a plausible explanation.  Others argue that over fishing coral reef fishes – especially those that graze down seaweed resulted in the blooms of algae.  Still others wonder if fish are important at all perhaps it was the decline in grazing long-spined sea urchins that resulted in the seaweed bloom.

The fact is, not all coral reef ecosystems have declined. The coral reefs in Bonaire remain relatively healthy with a high coral cover.  So, why have some (perhaps most) coral reefs declined but others remain healthy? 

Healthy coral reefs of Bonaire (note high coral cover, little seaweed)

Looking for the perfect laboratory
With this background, I sought to find the best place to explore the question of what’s plaguing the health of Caribbean coral reefs.  I focused on the low islands of the eastern Caribbean because they are dry and have little runoff, the Trade Winds and the north equatorial current bathes them in clear tropical seawater with a minimum of upstream pollution.  Since all of the eastern Caribbean islands are in a relatively small north to south archipelago, it is reasonable that global warming and ocean acidification will affect the reefs in similar ways.  So, by studying similar reef zones from island to island we can see if the reefs differ.  If they do, it likely the result of local factors such as the fish fauna rather than pollution, climate or atmospheric stresses.  This is not to say the other factors are unimportant but that they may not be the sole drivers of the health of coral reefs. 

The Caribbean.  Note the small dot to the north is Bermuda (image: Google Earth)

The Antilles of the eastern Caribbean.  My study sites for this expedition (image Google Earth)

How do you find the ‘pulse’ of a coral reef?  
For the last 20 years, several colleagues and I have worked to develop rapid assessment protocols for Caribbean coral reefs.  The gold standard for such assessments is the Atlantic and Gulf Rapid Reef Assessment known as “AGRRA” (http://www.agrra.org/index.html).  Over the years, research my students and I have conducted rapid assessments to characterize all the important reef organisms (especially coral, algae and fishes) with only a few dives per reef.  Since 1997 I’ve conducted AGRRA-like surveys in the Bahamas, St. Croix, St. John, Bonaire, Mexico, Belize, Honduras and Guatemala.  My work in Mexico along with AGRRA surveys at 38 other sites conducted by over 100 scientists was published in July 2003 in Atoll Research Bulletin (free to download at the AGRRA site). 

So by conducting rapid assessments on similar reef-types at the same depth allows us to determine if significant differences exist among reefs.  I'll get into the details of the differences we are looking for a bit later.  Nevertheless, if differences are found among islands, an excellent question would be, why are they different?  It is a bit premature for me to speculate on this but suffice to say, I do have a plan on how to proceed. 

Sunday, 27 October 2013

Bermuda's coral reefs

Lessons from a low diversity, isolated coral reef ecosystem

The northern most coral reefs in the world surround Bermuda.  In fact, the ‘footprint’ of  the island’s coral reefs is much larger than the island itself.  These reefs formed, as all coral reefs do, in shallow tropical seas.

Bermuda's coral reefs from space.  The green/brown 'fish hook' is Bermuda, the blue and darker circle are coral reefs.

 Corals are physiologically plants because of the tiny algae (called zooxanthellae) that live in their skin.  Those algae give the coral their color.  The algae feed the coral with sugars for growth and energy.  The coral provides habitat for the plants.  This symbiosis allows corals to grow toward the sun from a depth where they get enough light to grow.  It is actually a only a shallow depth band in which corals can live to get the light they need to grow.

Brain corals showing the color of their zooxanthellae

It is an accident of geology that causes Bermuda have these unusually expansive reefs. The island was formed by a volcano 100 million years ago but has since eroded down to a fraction of its former self.  Over the last million years, sea level has gone up and down with corals building up limestone layers each time conditions were right (underwater with abundant light) for coral reefs.  After the last ice age about 18,000 years ago, sea level was lower because lots of water was frozen at the poles.  When it rapidly melted, sea level rose faster than any coral could grow.  However, with time as the rate of sea level rise slowed the depth of the Bermuda bank was perfect for coral growth.

It is an accident of oceanography that Bermuda sits in warm tropical water capable of supporting coral reef growth.  Those two accidents of geology and oceanography resulted in the impressive coral reefs grew to what we see today.

Because Bermuda is 1000 miles from Caribbean coral reefs and is at the northern limit of coral distribution, there are fewer species of coral and of…. EVERYTHING... compared to typical Caribbean reefs.  For example, only about 20 species of coral live in Bermuda while 64 species are found in the Caribbean.

While coral reefs world wide are composed of a variety of shapes, Bermuda’s reefs are much simpler.   The reefs we saw today were strongly dominated by only a few species of brain corals.  Brain coral is so named because the grooves on the coral look a bit like the structure of a brain.  However, most brain corals are hemispherical.  So rather than seeing tree-like structures or complex branching shapes, we see a seascape of mounds. 
Brain corals mostly of the genus Diploria (for you science nerds)

The curious hemispheres of brain coral making the seascape of this Bermuda reef on the south shore
Grazing queen parrotfish and tang

Queen parrotfish over well grazed (see bite marks) reef surface
Stoplight parrotfish fleeing from me

The reef we saw was healthy.  There were lots of parrotfish grazing the algae to a thin turf.  That’s ideal but I’ll explain this in more detail later in the trip.  There were plenty of baby corals (small button size or golf ball sized corals). 

Bermuda has a low diversity reef as I explained above but that means it tends towards having monocultures.  The brain coral are mostly two species in one genus of reef coral.  It also may make it susceptible to non-native species introductions.  This has happened but one uninvited guest that did make it here is the now ubiquitous Pacific lionfish.  It is a beautiful fish with a nasty habit of eating baby reef fish.  It was introduced to Florida when Hurricane Andrew swept over the state in 1993.  It remained confined to that area for a while but then colonized the Bahamas to very high densities and quickly spread throughout the Caribbean.  No region I know has been spared.

Lionfish - the uninvited beautiful predator of baby fish

Friday, 25 October 2013

Off to Bermuda

OFF TO Bermuda

In Norfolk, Va ready to cross to Bermuda
Life at sea

Living on a 34’ boat has its challenges.  During long hauls, we sail 24 hours a day.  At all times someone is on watch.  We have to monitor where we are going, the direction of the wind and how we set our sails, other boat traffic, how much fuel, electricity and water we have.  Every nook and cranny is filled with provisions.  We have a packed refrigerator, a two-burner stove with oven and a barbeque grill.  A bimini protects us from the sun and provides a place for our solar panels.  It can be fully enclosed with several clear plastic panels that protect us from the weather but they also remove us from the environment.  With all this stuff, the challenge is not to get too complacent.

For coastal cruising we run 4 hour shifts (that is 4 hours on, 4 hours off) with teams of two.  For open ocean crossings one individual is on watch for 3 hours and then gets 9 hours off.  During the day as we cruise, we often chat about… well, everything.  So far, there’s rarely a debate.  At night, iPods come out, and the folks on watch work alone and without company.  After dark, we do not leave the cockpit to do something on the deck without waking a crew member to watch.  Then the person going forward, puts on his inflatable harness, clips it to the “jack line” (a flat strap that is secured to the outer deck of the boat from the forward cleats to the cockpit combing.  Jack lines are designed to keep you in the boat and tethered even if a large wave washes over the boat.

Sailing under light wind with carboys of extra water and fuel mounted on the starboard rail

We set out to Bermuda carrying fuel for three days of motoring but knowing the trip will be at least five days long.  We must sail and sail we did.  We had perfect sailing conditions, flat calm, and nearly gale force winds of 28 knots.  Nevertheless, we got into our 3 hours on, 9 hours off schedule – mine was from 9 to 12 (AM and PM).

Increasing winds and bashing waves at sunrise over the Atlantic

Meals are a big deal Ansley and Paul are great chefs so Curtis and I try to get out of their way and offer to clean up afterwards.  Meals range from chili to mahi mahi sushi (after Paul caught a mahi mahi).  Ansley seems able to whip up anything based on the first several things he found in the fridge.

Paul caught mahi mahi for lunch

The resulting sushi and sashimi

Crossing the Gulf Stream was a big deal.  For one thing, there are no other milestones at sea.  We had been cold crossing to the Gulf Stream and suddenly we were in cobalt blue tropical water!  Before we left we accessed "GRIB" files that model the current and predicted currents and temperatures (see photo below).  We knew where the Gulf Stream was expected to be and the blue dot on the chart showed us our current (GPS determined) location.  We were in t-shirts and shorts from then on.

Our track across the Gulf Stream (blue dot was our location when I took the photo)

Cruise track so far from the Damariscotta River to Bermuda.  Note the jog north reflecting crossing the Gulf Steam

Arriving to Bermuda's St. George harbor (left) and Customs house (right)

Alaria at the Customs dock after a 5 day 4 hour crossing

Thursday, 24 October 2013

Is getting there half the fun?

Is getting there half the fun?

The Long Road Down

Sailing from Maine to the eastern Caribbean is a trek.  It is 1,600 nautical miles as a crow flies but alas, we are not flying crows.  Under great conditions we will move at about 6 knots.  That’s a slow jog.  Again, this is only worth it if it means Alaria can function as a mobile marine laboratory along the entire eastern Caribbean coral reefs.

The Crew

The “long-haulers” are friends who are sailing with me to the Caribbean.  Once there, they will fly home and some or all may join me for the return.

The first day – we sailed to Cape Cod with five on board.  Ron Hunold (doctor), David Conover (videographer), Ansley Sawyer (retired dentist, now sailor), Curtis Smith (Arizona real estate agent, sailor) and me.  Ron and David left as planned after that leg and Paul Calder (writer-sailor) drove down to join us making the four long-haulers, Ansley, Curtis, Paul and me.  The student who joined me to conduct fish research is George Stoyle, a PhD student at the University of Newcastle, England who spent years conducting fish surveys in the Caribbean.  His dissertation research will be conducted on this cruise.  I’ll describe these folks in more detail later.

Pros and Cons of the Slow Road

For the same reason you don’t jog through museums, there are distinct advantages to moving over the ocean slowly on your way to work.  We departed Maine on Tuesday 2 October at 6 am with blue skies.   We watched both a sunset and sunrise over the ocean , we saw amazing bioluminescence and were surprised to find a needle-like “ballyhoo” fish jumped into our dingy over night.  A pod of dolphins escorted us out of the Gulf of Maine.  New York City was a hoot  - my sister ran down to wave as we rode the rapids called the East River.  We sailed past the Statue of Liberty in all of her glory as we dodged monster cargo ships and ferries. 

 Ballyhoo in the Gulf of Maine!
 New York City.  Paul watches skyscrapers go by.  Statute of Liberty watches us go by.

The Jersey shore kicked our butts. Big steep-sided seas had us rocking and rolling along the Garden State.  We ducked into Cape May (southern-most NJ) just as a huge front was approaching.  Remnants of Hurricane Karen did little on land, but the ocean is a different story. Big seas offshore forced us to sail up the Delaware Bay, cut across the Chesapeake-Delaware Canal and then sail down the Chesapeake.  We arrived in Annapolis to see flags and banners heralding the start of the Annapolis Boat Show, the largest in water boat show in the US.  There, we reprovisioned, went to the boat show and waited for the weather to improve offshore.  A fortuitous get together with Paul's father Nigel Calder ended with dinner and a toast for good luck sailing.  We sailed onto Norfolk Virginia adjacent to the huge US Navy base where we set out for Bermuda. 
The Annapolis Boat Show

A toast with Curtis Smith, Nigel Calder and Ansley Sawyer

There be fewer dragons now

History is replete with seafaring myths of serpents, mermaids and the Bermuda Triangle.  These are things we cannot see but only imagine in our vast ocean.  However, technological evolution leaves relatively little for over-active imaginations.  It is not just that remarkable technology exists, it is that it is now in the hands of common folk like us.  For example now global positioning systems are now found in every I-pad, new software, satellite images and communication systems means that there are fewer unknowns.  We can now look at weather patterns and find weather predictions that only experts could make in the past.  It is still important to be vigilant.  It is still necessary to know seamanship and have a vessel ready for long ocean crossings.  But the chances of sailing into a monster storm that shows no symptoms on shore is much lower with today.  Tiny Alaria (34 feet long) has for our journey a GPS chart-plotter, radar, Automatic Identification System (AIS), EPIRB – satellite emergency beacon, an InReach satellite communicator, six on-board computers loaded with navigation and weather prediction software.  The list goes on but you see my point.  In fact, electronics are so important that we built a charging station that can charge all of our on-board electronics.  Nevertheless, we still have paper charts, parallel rules and everything we need for navigation should we have complete electronics failure.   Oh yes, we also have several GoPro cameras so if we do see any dragons, they will be filmed.

 Cockpit view of chart plotter, autopilot, compass, wind indicator etc.

Charging computers, Ipad, Ipod, I don't know what else...

Wednesday, 23 October 2013

Seeking the pulse of Antillean coral reefs

Seeking the Pulse of Antillean Coral Reefs

The journey:

Technology shrinks our world.  We chat with folks electronically all over our planet without giving it a second thought.  We can fly almost anywhere in a day.  Our concerns are less on how we get somewhere than how we deal with the jet-lag of having jumped a dozen time zones.  Mine is a slow journey sailing to and through the eastern Caribbean to study remote and hard to get to coral reefs there.  This is my attempt to explain it to you.

 Alaria the 34' cutter rigged sloop before being converted to a research vessel

The impetus:

Sailing to the Caribbean means travelling at walking speed but without the comfort of terra firma.  It is a slow, bumpy and uncertain road -– so why do it?  There are several answers.  First, this is a science project that needs to be done.  In May 2012 a meeting of leading coral reef scientists reported on trends in the health of Caribbean coral reefs over the past 40 years.  It was clear that coral reefs have changed profoundly in many areas but the stories of why they changed are complicated.  I was amazed to realize that no one reported on reefs of the eastern Caribbean.  That was not because there are no reefs (historically some of the best reefs are found there), but because there are no marine laboratories in the region.  Second, trying to assess stresses on reefs that cause them to decline becomes complicated when polluting countries are up-stream of the reef you are studying. It occurred to me that the trade-winds and ocean currents make each island biologically isolated from adjacent islands.  Whereas regional climate effects on reefs would be wide-spread, the differences among reefs of islands likely relate to how land and reef ecosystems have been managed locally.  Thus the eastern Caribbean is the best place to study the causes of reef decline and opportunities to improve their management. It seemed to me that to address this problem, I needed a way to study a number of independent coral reefs in the Antillean archipelago to see if I can determine trends that relate to how different islands (and countries) manage their coral reefs.

The type of research needed to be done on eastern Caribbean reefs is similar to work I’ve been conducting elsewhere for decades.  It is low-tech, can be done with little or no laboratory space and can be applied rapidly at each study reef.  However, making it work from a small sailboat, created the most logistically complex project of my life.  I need to get my sailboat Alaria  down to the Caribbean and ready to conduct reef research.  For this I need to outfit it for tropical research and I need  a “long-haul” crew to sail with me from Maine to the Caribbean.  I will also need a dive buddy and help conducting this research.  Believe me, the number of folks who would volunteer to help me in my research is huge but I want someone who is good with reef fish and will advance his or her career goals by joining me on this trip.   Specifically, I want to find a student who can do quantitative surveys of reef fish as I do all other reef creatures from corals to the animals and plants with which they live. 

Painting the hull

Tuning the engine

Preparing Alaria's hull, engine and launching  

The sailboat Alaria is a 34’ cutter-rigged Pacific Seacraft.  It required a year of preparation getting the engine overhauled, rigging on the boat replaced, new electronics and a compressor for scuba diving had to be installed.  I discussed the possibility of sailing to the Caribbean with lots of folks I know.  I asked colleagues in the field of coral reef research to suggest students who would profit from this research opportunity.  Somehow, all the pieces fell together and we shoved off for the Caribbean 2 October 2013.

Launching Alaria
 Alaria ready to go with wind generator, bimini top, solar panel, self steering mechanism

 Last night in Maine
Three of the intrepid crew (Paul Calder, Ansley Sawyer and Bob Steneck) right to left.