zmt Bremen


Pazifikküste, Costa Rica, 13.1.12 – 1.2.12

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Golfo Dulce, air temperature 32 °C, water temperature 28 °C

We started the day at 7 am with a short breakfast before we rented a boat to go to the “place with the bubbles”. After about one hour travel time, we arrived close to the opening of Golfo Dulce into the Pacific in the middle of the Golfo. Here, we intensely looked for the bubbles and finally (after about 1 h of searching) detected some on the surface. We jumped into the water as soon as possible in order to explore what is going on down there. To our surprise, at ca. 10 m water depths there were the most extensive healthy Porites coral communities that we have seen since we are here in Costa Rica. The coral communities were growing on some kind of plateau and surrounded by very soft, organic rich, muddy sediments. A multiplicity of gas bubbles was coming out from both the Porites community and the surrounding seafloor. We of course started to collect water close to the bubble sources and brought the samples back to the ship where we measured the CO2 partial pressure in these samples. To our surprise, this did not show any values above the background, so that the gas bubbles could not be CO2. After a short discussion, we decided that we should get the gas directly to identify what it was. We therefore went down again and collected the gas in glass bottles. After return from the trip, we bought a pack of matches to bring the gas in contact with fire. The collected gas from the reef was indeed slowly burning with a blue flame – this must be methane!

Although we could not find CO2 emissions, we are fascinated by our recent exploration of cold methane seeps in a living shallow-water coral community. We wanted to study the future, but this could mean that we are now going to study the past…

This pilot expedition to Costa Rica has been an amazing experience for all of us, but particularly for our Italian research snorkeler that saw his first living corals in the wild. PURA VIDA!

Christian Wild

The Alka Seltzer Reef

Collection of gas samples using glass vials

Methane fire proof

The team


Manuel Antonio, air temperature 27 °C, water temperature 27 °C

On our desperate search for intact coral reefs we continued our trip to the South early this morning. After a 4 h drive (last hour on a dirt road) we finally arrived at the Eastern tip of Golfo Dulce, a large fjord-like basin surrounded by mangroves and green hills, with just a few villages and coastal developments. We checked in at an Eco Resort where we could rent the last cabana where we shared an open bed room together with 4 people just separated from the jungle by a mosquito net.

Our afternoon snorkeling excursion to the adjacent fringing reefs in the Southern Golfo Dulce unfortunately revealed almost no living corals, except a few heavily damaged massive Porites colonies. According to the descriptions of our Costa Rican colleagues, reasons for this sad massive reef degradation is likely a combination of the El Nino warming event in end 2010 and intense sedimentation of matter from recent building of a street close by on land. Tomorrow, we aim to explore the Northern site of the Golf and find out if the situation is similar there. We also got the very interesting and exciting information that CO2 seeps occur there. This in combination with living corals could mean that the Golfo Dulce may be a perfect natural laboratory to study effects of acidification on coral metabolism. However, after the experience of the last days we are a bit skeptic about the health condition of local coral reefs. Let’s see what we will experience tomorrow morning.

Christian Wild

Our accomodation for tonigth in the jungle

Our bed room

28. - 29.1.12

Playa del Coco, air temperature 31 °C, water temperature 27 °C

We started our trip to the South early this morning. After a 7 h drive along the coast passing by large mangrove areas and extensive palm oil monocultures we finally arrived at Manuel Antonio, a little village located between the green jungle hills and the ocean. Manuel Antonio will potentially be the central station on our pH gradient along the Costa Rican Pacific coast. Therefore, we plan to do another set of measurements of the carbonate system in the water supported by additional observations of the local coral reefs.

Playa Manuel Antonio, air temperature 32 °C, water temperature 28 °C

Today, the water chemistry team around Tim Rixen left early in the morning in order to set up the measuring system as soon as possible on the rocky beach of Playa Manuel Antonio. Measurement of pH and partial pressure of carbon dioxide started at 7 am and went on successfully until dawn at around 6 pm. The coral reef ecology and ecological modeling team joined soon after and inspected the coral reefs announced by our colleagues from University of Costa Rica.

Unfortunately, there were no coral reefs, only some large colonies of the massive coral genus Porites that were highly overgrown by brown macroalgae. Sadly, we were realizing that the Pacific coral reefs of Costa Rica obviously undergo fast degradation processes. Therefore, we will not select Manuel Antonio as study site for our project. On the way back through the jungle we were surprised about the multiplicity of beautiful wild animals including green tree frogs, different monkeys and sloths (please see pictures).

We are hoping that we will see some remaining intact reefs on our upcoming trip to Golfo Dulce in the South.

Christian Wild

Tim Rixen measuring the carbonate system in Bahia Manuel Antonio

Research snorkelers inspecting Porites coral colony

Sloth with baby

White face monkey


Marina Papagayo, Guanacaste province, 32 °C

The Bahía Culebra is a bay embraced by the peninsula de Papagayo in the Guanacaste province of Costa Rica. The peninsula was formed by volcanic activity and is characterized by tropical dry forests and beautiful beaches.

At 10:00 today we reached the Marina de Papagayo in the Bahía Culebra. To our great surprise the marina was invaded by a red tide. The phenomenon has been observed in this area for the first time in April 2000 and it has become more and more frequent in the last years. Tim and I spent the entire morning trying to set up a CO2 sensor and other instruments, including pH and salinity meters. We succeeded in making the sensors work just in time for lunch! We measured unusually low values of CO2 in the water (around 220 ppm) probably indicating the presence of a bloom by photosynthesizing algae. Generally red-tide blooms are produced by heterotrophic dinoflagellates, which are not supposed to reduce CO2 in the water. A really intriguing situation.

In the afternoon we received visitors, a rather inquisitive spiny-tailed black iguana (see photo) came to look at us. In Costa Rica there are two different types of iguanas: the green iguana (Iguana iguana) and the spiny-tailed black iguana (Ctenosaura similis). The black iguana, probably the fastest running lizard on Earth, is omnivorous, eating leaves, fruits, flowers, insects, crabs and lizards. The iguanas normally sleep during the night and spend the day lazily basking in the sun, but this one was obviously looking for some excitement...

Agostino Merico, Tim Rixen

Tim Rixen setting up the CO2 sensor.

CO2 sensor at work below the green curtain.

Spiny-tailed black iguana visiting the measuring site...


Palmitas and Playa Blanca (Culebra Bay, Guacaste)

Today, we visited two sites in Culebra Bay, one at the outer and the other at the inside of the bay.

The first place was Palmitas, an antique coral reef, which has experienced a massive mortality potentially caused by a harmful algal bloom (red tide) in 2007. This bloom developed during the rainy season and affected the reef for at least two weeks. We carried out two intercept chain transects in this place in order to estimate the percentage of coverage of the different substrates, groups of reef organisms, and their condition. Life corals could not be found and dead coral mainly formed the substrate. The skeletons of the dead corals were mainly overgrown by calcareous algae and to minor extend by fleshy macroalgae.

After finishing the transects, we explored a small coral community growing on basaltic rocks in the vicinity of the reef. This community was mainly formed by Pavona clavus, a common massive coral species, and some octocorals that were mostly dead and partly overgrown by cyanobacteria. We could observe two Pocillopora sexual recruits and took a water sample to measure dissolved oxygen and pH.

After our work in Palmitas, we moved on to Playa Blanca, located at the inner section of the bay. Here we also did a couple of transects and explored two coral reef patches. Similar to Palmitas, Playa Blanca also experienced a severe mortality event. The major difference between Playa Blanca and Palmitas is that the reef in Playa Blanca is recovering. Several live colonies of the branching coral Pocillopora could be observed inside the reef and over the sand bottom adjacent to the reef. The estimated percentage coverage of live coral in the reef was less than 10%. Another difference is the high abundance of sea urchins (Diadema mexicanum) over the coral skeletons in Playa Blanca.

The major concern about coral reefs in Culebra Bay is the slow recovery rate as seen in Playa Blanca and even the absence of any indication of recovery in Palmitas. This might be caused by the frequent occurrence of red tides and the high density of the invasive macroalga Caulerpa sertulariodes. The increasing frequency of red tides could be related to the coastal development and the inappropriate management of sewage waters.

Celeste Sanchez (Costa Rican guest author)

Dead reef at site Palmita with observing local research diver

Gang of Diadema sea urchins

Caulerpa algae greens dominated the seafloor

Dense Pocillopora communities close to Play Blanca


Cuaquinicil village, Guanacaste region

Today we went to Cuaquinicil, a fishing village close to the Nicaraguan border. It is a place with a rather short history: 50 years! Before that time only a couple of families were living there, dedicating their lives as workers on the farm of Somosa (the notorious Nicaraguan land-lord), who owned land in Guanacaste. With time, these few families have grown into a village of roughly 1500 fishermen and their families (numbers have been quite contradictory, but this looks reasonable). A good portion of the people has Nicaraguan origins. Most of the people live directly or at least indirectly from fishing, three or four families live from tourism diving activities and a handful of others from restaurants or other related tourism activities. Roughly 10% go by bus to Liberia or La Cruz for working.

There are three different general forms of fishing. Fish diving is the first, often done with a compressor under very unsecure and dangerous conditions, many divers die of this. The association of diving fishermen used to have 60 members in former times but now they are only 6. Their daily income from fishing is roughly 3000 Colones, approximately 6 USD. The other fishing technique adopted is by using nets on two to three meter long boats for 4 to 5 days along the Coast. The third technique could be probably defined as semi-industrial (see picture). They are going out up to 500 miles off shore and stay out for 20-30 days on boats with 4 people. The owners of the boat never join the fisherman for fishing. After having subtracted the costs (the fishermen don’t get any salary), 50% or more is for the owner of the boat and the rest is divided by the 4-crew members. The salary of a fisherman for one cruise is between 0 and 160 USD.

The community seems to be squeezed in between the Nicaraguan border on the north and a Marine Protected Area on the south. Therefore, they either have to go very far or they have a rather restricted fishing ground. There seems to be severe overfishing and catches are miserable since 2005. Many fishermen are going to other waters to fish (Samara), where violent conflicts emerge. Particularly annoying for the people in Samara is the diving with the compressors used by Cuaquinicil fishermen (brought by the Chinese 25 years ago, so that the fishermen could fish sea cucumber; strangeness of the globalised world, because Costa Rica has not direct demand for it) and is not used by people in Samara. Diving at night and with the help of a compressor one can easily catch a good proportion of fish. The community seems to be blocked and not developing. People do not know what else to do. Mainor Lara, a villager we interviewed in Cuaquinicil, is operating a diving business for tourists and seems to be able to make a good living out of it. Mainor also criticized the other fishermen in their race to the bottom, which obviously is not good for his tourism diving business.

This fishing village probably was affected by at least two important shocks. One, as mentioned, was the installation of the Marine Protected Area, the other also going on at present is the massive immigration of Nicaraguan people. The latter might be a reason, why cooperation does not seem to play a major role in their management efforts, but rather everybody tries to get as much as possible without caring too much about the common resources. Definitely, there are many things we do not know still, but the experience has given us a very interesting first insight.

One last thing: the manager of the marina we visited yesterday spoke about the communities nearby as people who cannot be integrated at least until they get a proper education… This was definitely not the impression we got in Cuaquinicil. One mother of seven children, for example, who was responsible for selling the subsidized fuel to the fishermen, reported proudly on the studies her children have done at Universities. There was a clear vision that children should have a better life than the parents and that this may come only through a better education.

Agostino Merico, Achim Schlüter


Fishermens´ berth on board

A fisherman´s house

Ago, Achim and a local fisherman


Playa del Coco, air temperature 32 °C

Today, the team (except Ago and Achim that visited some interesting local communities that are catching their fish by hand further North) chartered a boat in order to have a look on the coral reefs in the neighboring area. When we jumped into the water at the first site, we were shocked about the condition of the reef. The very dense populations of the scleractinian coral Pocillopora were either dying at the moment (visible as tissue abrations) or already dead. In some areas of the reef algae (particularly red coralline algae and fleshy green algae of the genus Caulerpa) had overgrown dead coral colonies. When we talked to our colleagues from Costa Rica about these observations we learned that they think that red tides (blooms of toxic dinoflagellates) had caused the recent coral death. Reasons for the extensive blooms in their opinion were nutrient inputs from the many hotels distributed along the coasts. This is something we will definitely follow up in our upcoming research projects.

The second location we then visited was strongly exposed to the seasonal upwelling induced by strong winds during this time of the year. However, today we were lucky and had a calm day. We also observed a reef almost without any scleractinian corals. Instead, other organisms such as fleshy red and green algae were dominating the seascape. Most interesting to us (apart from a turtle, a nurse shark and a beautiful eagle ray that all passed us) was the occurrence of calcifying green algae of the genus Halimeda that were highly flexible and appeared to be very soft when we touched them. We assume that this is a consequence of the upwelling transporting acidic water to the surface so that calcification processes are impeded. Based on these hypotheses, the interdisciplinary team of coral reef ecologists and biogeochemists immediately developed ideas for the two upcoming PhD studens within this joint Costa Rican-German project.

Christian Wild

Playa del Coco

Dying reef

Butter soft Halimeda

Sediment sampling by local research diver

The ZMT team in front of the research vessel


Golfo de Papagaya, air temperature 33 °C

On our 6 h trip from San José to the Northwestern coast of Costa Rica we realized that it got warmer from km to km due to the fact that San José is located at more than 1000 m above sea surface. At 3 pm we finally arrived at Marina de Papagaya, a new large scale coastal development project in this area. The operation manager was already waiting for us to give us a presentation about the marina project and its sustainability. Obviously, the investor had tried to minimize the building impact and invested in education measures for the local communities.

Christian Wild


Playa de Coco, Pacific Coast

Today we discussed with somebody from WWF, Conservation International and a local representative of the Ministry of the Environment, section protected areas, getting a first impression of what are the worries of the fishermen here. It seems to be as Mancur Olson (theorist of collective action) would predict. There are a lot of small fishermen, who don’t get organized. Therefore, they are not able to defend their interests neither in the day to day business nor on the political scene.

The regulating body of the fishing sector (incopesca) is dominated by a rather small quantity of industrial fishermen. Their interests are heard and they are able to influence politics. The industrial fishermen (camaroneros) are quicker than the others and are fishing with their nets, which have too small holes, also a lot of fishes which are vital for the small fishermen.

There seems to be also a conflict between compressor-diving fishermen and tourism operator divers. The first follow the latter, then catching all the nice fishes. This obviously does not amuse the tourism divers, because they can’t make their clients happy anymore when the fish end up in the stomach of the tourists at dinner.

A rather common adaptation strategy, particularly for the fishermen in the North, is to go on the move when scarcity increases. So, many communities seem to have any form of informal management rules for those living in the community. But when scarcity becomes too big, they start to move up and down the entire pacific coast. They stay away from home for quite a while and are in close contact with their traders, who pick the fish up at the bay where they are.

Within the literature this phenomenon is called “rowing bandits”. The rowing bandit harvests as many resources as he can in one place (which is not his own), and then moves on to the next. One can imagine that organizing collective action or cooperation with people who show this type of behavior is rather difficult. These are just first impressions and they have to be backed up by many more observations. Tomorrow we will speak with different fishermen and diving operators in a small village.

Achim Schlüter


San José, CIMAR, Universidad de Costa Rica, blue sky, air temperature 20 °C

Today, the mini-symposium „Adaptation of coral reefs to changes in carbonate chemistry – the Costa Rican Pacific coast - an analog for the future?” was supposed to start at 8.30, but due to an electricity black-out many participants had problems to arrive in time. We introduced ourselves to everybody and started the meeting at 9.00.

Former director of CIMAR, José Antonio Vargas, opened the symposium with a welcome speech in which he mentioned the long lasting partnership between CIMAR and ZMT (actually started 20 years ago by Matthias Wolff), the intense exchange of students, and joint research projects.
This speech was followed by a series of talks from CIMAR and ZMT scientists describing the status of coral reefs on the Costa Rican Pacific coast, the scientific background of ocean acidification and many other different talks presenting the ample expertise of the symposium participants.

Thereby we explored the collaboration potential and synergies among the various researchers. The symposium was then concluded by an intensive discussion among the participants, where a lot of ideas emerged on how the joint research efforts could develop. CIMAR vice director Jorge Cortés was particularly enthusiastic about this collaboration (which seems to be the effect of the long term trust and working relationship developed with Tim Rixen). ”A good and open working relationship is essential for our collaboration”, emphasized Jorge Cortés. All in all we felt very much welcomed and at home in Costa Rica and in particular at CIMAR. We agreed that we will meet again at CIMAR with Jorge Cortes after our field trips in order to continue in more detail the discussion on how the collaborative project should develop in the next months.

Tomorrow we are leaving to the field, Bahía Culebra, in the Golfo de Papagayo, located at the Northern Pacific coast of Costa Rica, where we expect to observe strong seasonal upwelling now. We therefore plan to do some key measurements there and explore what kind of experimental work is feasible. We will send another post on our observations from there as soon as we have internet access.
A special thanks goes to the organizers of the symposium and the pilot surveys, Carlos Jimenez (CIMAR) and Tim Rixen (ZMT).

Christian Wild

Jorge Cortés

Listening audience with two organisers left


Turrialba/San Jose Costa Rica

I am currently for two weeks in Costa Rica, a country about which I am working since 4 years. The first week I mainly spent with my PhD student Roger Madrigal, who is now working at CATIE in Turrialba and we worked about “our turtles”. The next week we are exploring with our partners from the Universidad de Costa Rica and my colleagues Agostino Merico, Christian Wild and Tim Rixen (a truly interdisciplinary venture - every ZMT department is represented), what might be investigated in relation to ocean acidification in Costa Rica. We will report on the latter in the days to come.

So let me now report on the first week. The duty was to discuss the final stage of Roger’s PhD. He focuses on community governance. Traditionally the Costa Rican state has not given much importance and recognition on local governance, regarding people actually using the resources, but used a more centralistic approach. However, due to resource characteristics, better knowledge, better abilities of monitoring etc. in certain cases it is useful to organize the management of common pool resources on a local level. We were looking to local water provision on the one side and to a community called Ostional, which after severe fights with the government got the right granted to extract turtles´ eggs under very strict conditions.

Over the last year we made an inventory of rules governing the local system and focusing then particularly on sanctioning rules, always very important for institutional systems to work. This year we expend our work to Nicaragua, where the same species is arriving. However, a completely different approach to management is used. There the local communities have no right to extract any eggs, however, informally the extraction levels are extremely high. Therefore, an NGO started a performance based payment scheme: paying money to fishermen (or should one say poacher?), mostly above the market price for turtles´ eggs, if they don’t bring the eggs of a nest to the market, but to the NGO (Paso Pacifico). We had the possibility half a year ago to convince ourselves that this is an interesting program showing some effects.

However, this week we were starting to design an experiment, which allows to test if this policy is reaching its goal, increasing the amount of little turtles, which hatch from the beach. As the project is restricted to certain beaches it might be that poaching is just transferred to other beaches. Or it might be that even now more people are attracted into the “business”, as it becomes a recognized activity to collect turtles´ eggs, even if it is not for selling or eating. However, it is also very likely that this performance based payment is actually the most cost-effective tool for protecting the turtles. At the moment we are still in the design phase, but in July our research will be put in place. In the long run a comparison between Costa Rica and Nicaragua and a comparison of policy options is planned (a sanction; a positive incentives or environmental awareness raising). But these are plans to come…

Tomorrow or the day after tomorrow a report will come on our acidification workshop at the Universidad de Costa Rica in San Jose. My duty will be to describe the event from the perspective of a social scientist. Let us see how this interdisciplinary venture will succeed.

Achim Schlüter

Agostino Merico, WG Systems Ecology
Christian Wild, WG Coral Reef Ecology
Achim Schlüter, WG Institutional and Behavioural Economics
Tim Rixen, WG Carbon and Nutrient Cycling