Aquatic Health, Marine Conservation

Aquaculture: A Sustainable Solution to the Global Seafood Crisis?

By: Clara Gomez

The world’s seafood stocks will have completely collapsed by the year 2050, scientists say.  According to a study done by a group of economists and ecologists, the growth of the human population combined with unsustainable fishing practices and the devastating loss of biodiversity will lead to the collapse of fish populations in the next 35 years, if trends continue on their current path.

If the idea of losing all of the world’s fish scares you as much as it scares me, then you’re wondering how we disrupt the current “trend” of unsustainable overfishing.  One option is through the use of aquaculture.  Aquaculture, also known as fish or shellfish farming refers to the breeding, rearing, and harvesting of plants and animals of water environments including ponds, rivers, lakes and the ocean.  

Although the global community is just beginning to think of aquaculture as a potential solution to the dilemma of depleted oceans, the fact is that it’s not a new practice. In fact, although historians say that the cradle of aquaculture existed in China 4,000 years ago, recent archaeological evidence (2003) suggests that the Gunditjmara tribe of Australia already had a system to raise and cultivate eels in in the southeast of the country 8,000 years ago.  The system was so efficient (after being designed as an alternative method for procuring food) that traditional practices remained stable throughout history!! Or at least not until Stephan Ludwig Jacobi appeared on the scene, at some point in the early XVIII century.

Thanks to Jacobi and his article ‘Von der künstlichen Erzeugung der Forellen und Lachse’, aquaculture became a part of mainstream science due to the success based off of his experiments in the external fertilization of trout and salmon. Not only in terms of self-sustainability, but also of commerce at an industrial level. From then on all manner of projects and investments began, and thus was born the second generation of aquaculture─ the modern aquaculture we all know today, and which is currently reinventing itself to adapt to a society increasingly aware of its impact on the environment.

Part of this shift in the way aquaculture utilized is the utilization of what’s called Integrated, multi-trophic aquaculture.  While it sounds complicated, it’s an idea that involves the raising of diverse organisms within the same farming system, where each species utilizes a distinct niche and distinct resources within the farming complex.  This allows the fish to be raised in a much more biodiverse, nature-like setting. Additionally, this system utilizes a circular economy–the idea that the waste from one product serves as nutrients for another.  So, raising plants and fish together both cuts down on cost and waste. This current of change, in conjunction with the holistic approach that Osa Conservation has in regards to conservation, is what prompted the organization to plan the future fusion between a multi-trophic aquaculture project (still in development), and its already successful sustainable agriculture program. A large number of scientific publications (many published by the Food and Agriculture Organization of the United Nations) support these projects, and the tropical climate of Costa Rica is perfect for local breeding of sea creatures.  What’s the harm in trying?aquaculture, circular economy

If successful, this new project of integrated, multi trophic aquaculture would be extremely beneficial in the following three areas:

Ecology:

The integrated, multi-trophic aquaculture system mimics the relationships among organisms in the natural world (not just by raising aquatic organisms and terrestrial plants together, but also by using one organism’s waste as input for others).  It also ensures both the optimal use of resources and the reduction of water pollution and eutrophication levels.

Economy:

This new and improved system of aquaculture represents a positive step towards the self-sufficiency of Osa Conservation, and as such also represents a reduction of costs in terms of food imports from San Jose. Likewise, the implementation of a new food cultivation system could mean new employment opportunities for locals.

Pedagogy:

Not only is the integrated, multi-trophic aquaculture system is easy to understand, but it has the potential  to include human waste as part of its cycle. That means that both the system’s facilities (eg tanks external fertilization, duck ponds, rice fields, etc) as food produced through it (eg shrimp species, and native fish) have potential to serve as educational material for both the local community and visitors of Osa. What better way is there to learn about aquaculture, than to see how everything works and then personally taste the final product?  Adopting a system of aquaculture in the Osa will allow OC to expand upon its teaching capacity and further embody its own standards of sustainability.  

 

Sources

1.“Aborigines may have farmed eels, built huts” ABC Science Australia:http://www.abc.net.au/science/news/stories/s806276.htm

2.“Analysis of the Aquaculture Market in the Costa Rican Metropolitan Area. Instituto Costarricense de Pesca y Acuicultura (2010): https://www.wpi.edu/Pubs/E-project/Available/E-project-121410-115309/unrestricted/Analysis_of_the_Aquaculture_Market_in_the_Costa_Rican_Metropolitan_Area.pdf

  1. “At a Crossroads: Will Aquaculture Fulfill thePromise of the Blue Revolution?” (SeaWeb Aquaculture Clearinghouse report, PDF): http://www.seaweb.org/resources/documents/reports_crossroads.pdf
  2. “Biomass Accumulation and Water Purification of Water Spinach Planted on Water Surface by Floating Beds for Treating Biogas Slurry”Journal of Environmental Protection (2013, PDF): http://file.scirp.org/pdf/JEP_2013111911133739.pdf

5.“Contribución de la pesca y la acuicultura a la seguridad alimentaria y el ingreso familiar en Centroamérica” Organización de las Naciones Unidas para la Agricultura y la Alimentación — FAO  (2014,PDF): http://www.fao.org/3/a-i3757s.pdf

6.“Culture of Fish in Rice Fields” (FAO, WorldFish Center. 2014) PDF:http://www.fao.org/docrep/015/a0823e/a0823e.pdf

7.“History of Agriculture” FAO Corporate Document Repository. http://www.fao.org/docrep/field/009/ag158e/AG158E01.htm

  1. FAO “Animal-Fish Systems: Integrated Fish-duck farming”

    http://www.fao.org/docrep/005/Y1187E/y1187e14.htm

9.“Food from the sea. Remarkable results of the experiments in cod and lobster,(Pittsburgh Dispatch. aquaculture, 1890): https://www.newspapers.com/clip/3798097/food_from_the_sea_remarkable_results/

  1. Integrated Multi-Trophic Aquaculture: What it is, and why you should care…..

and don’t confuse it with polyculture. (2006, PDF): http://www2.unb.ca/chopinlab/articles/files/Northern%20Aquaculture%20IMTA%20July%2006.pdf

11.National Oceanic and Atmospheric Atmenistration (NOAA): http://www.nmfs.noaa.gov/aquaculture/what_is_aquaculture.html

  1. All Seafood Will Run Out in 2050, scientists Say (Charles Clover, 2006)

http://www.telegraph.co.uk/news/uknews/1533125/All-seafood-will-run-out-in-2050-say-scientists.html

Marine Conservation, Science and Research

Osa Conservation Supports Research in Golfo Dulce: Drawing Conclusions

Mogos Islands mark the highest waters of Golfo Dulce.

By Brooke Bessesen

While Jorge and I both loved working on the water, the results of our research brought the greatest rewards. Golfo Dulce is a true bio-gem—one of Costa Rica’s preeminent riches. Several hundred Green sea turtles, critically endangered Hawksbill sea turtles, Olive Ridley sea turtles and (reportedly) Pacific Leatherback sea turtles, rest, feed, mate and nest in the gulf. A rare xanthic colony of pelagic sea snakes resides around the inner basin. Both Northern and Southern Hemisphere Humpback whales enter the inlet to give birth and possibly provide sanctuary for young calves. Whale sharks aggregate in Golfo Dulce. Resident dolphins and other toothed cetaceans breed and raise offspring. Scalloped hammerhead sharks are born there and needlefish spawn. What a remarkably vibrant bionetwork!

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Marine Conservation, Science and Research

Osa Conservation Supports Research in Golfo Dulce: More Species, More Understanding

By Brooke Bessesen

The name “Brown pelican” belies the attractive hues of a mature bird.

I’m sure it comes as no surprise that during our 400+ hours of observation in Golfo Dulce, Jorge and I witnessed an astonishing array of marine life. Indeed, we were astounded by the intense biodiversity revealed to us during our research. In addition to the animals I’ve already blogged about in this series, many more are worth mentioning. Some were officially documented, others were not, but all helped define our emerging portrait of Golfo Dulce.

Brown pelicans (Pelecanus occidentalis) are commonly seen in Golfo Dulce and we located a year-round communal roosting area along the banks of Piedras Blancas National Park in the upper half of Golfo Dulce. We saw many other marine birds, too, including Brown boobies, magnificent frigates, osprey, several species of gulls, terns, swallows, herons, ibis and dozens more wading and estuary birds.

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Marine Conservation, Science and Research

Osa Conservation Supports Research in Golfo Dulce: Different kinds of dolphins

A video still of a Pseudorca, or false killer whale, in Golfo Dulce

Brooke Bessesen conducted Marine research at the Osa in 2010 and 2011 as a recipient of the Greg Gund Memorial Fellowship. Check out her Golfo Dulce report on our website.

Jorge and I were always thrilled to see dolphins, as they are icons of the sea. Luckily, sightings were relatively common (only sea turtles were seen more frequently) and these graceful cetaceans graced our bow almost every day we were on the water. We observed many dolphin behaviors: foraging and traveling, mating and calf care, spyhopping and playing. But, of course, dolphins are not all same.

The most common delphinids seen in Golfo Dulce were Bottlenose dolphins (Turciops truncatus) followed by Spotted dolphins (Stenella attennata). Even though some Spotted dolphins don’t have spots, these two species are fairly easy to tell apart. Spotted dolphins are smaller in body size and have distinctly sickle-shaped dorsal fins. There are behavioral differences, too.

Most of the Bottlenose dolphins in Golfo Dulce appear residential and some even seem to show fidelity to certain parts of the embayment. This species tends to hang out more coastally, especially near river outlets, sometimes chasing ballyhoo and needlefish at the surface. While they occasionally converged into congregations of five to 15, the Bottlenose dolphins were usually seen in smaller groups of two or three.

Spotted dolphinsmigrate in and out of Golfo Dulce, generally using the deeper middle waters of the inlet. The average

A young spotted dolphin speeds along next to our research vessel

group recorded during our survey was five to 60 individuals; however, we recorded several sightings of scattered herds estimated to include 100 to 500 individuals. At times large groups of these gregarious cetaceans could be seen playfully flinging themselves into the air, a show-stopping riot of activity.

A sighting of False killer whales (Pseudorca crassidens) was also made during our study period while aboard the vessel of Project Golfo Dulce Wildlife. We followed about 30 individuals, adults and at least one calf, as they traveling and foraging between Sándalo and Playa Blanca in the upper half of the gulf.

It is also interesting to note that Spinner dolphins (Stenella longirostris) and Short-beaked common dolphins (Delphinus delphis) have been reported inside Golfo Dulce.

A playful Bottlenose dolphin leaps into the air (insert shows the shape of a Bottlenose dorsal).

Dolphins are arguably the most delightful animals to watch. While seeing them is always a thrill, it’s even more exciting to be able to distinguish the species and have enough knowledge about behavior to fully enjoy their aquatic antics.

Marine Conservation, Science and Research

Osa Conservation Supports Research in Golfo Dulce: So Many Sea Turtles!

Side by side, you can begin to see the characteristics that visibly differentiate the three sea turtle species we documented inside Golfo Dulce.

When we began our research, nobody expected us to find very many sea turtles inside Golfo Dulce — most sea turtle activity was thought to occur on the Pacific side of the Osa Peninsula. It turned out that chelonids were the most frequently seen family of animals, accounting for 38 percent of our total sightings. Discovering such significant numbers of sea turtles was one of our most important findings. Sadly, fishermen with many years of experience in Golfo Dulce say the sea turtles there have declined at least 30 percent in recent years.

Jorge and I documented three species: Pacific Black sea turtles, still commonly referred to as “Greens” (Chelonia mydas agassizii), Olive Ridley sea turtles (Lepidochelys olivacea) and Hawksbill sea turtles (Eretmochelys imbricata). Locals also reported seeing near-extinct Pacific Leatherback sea turtles (Dermochelys coriacea) inside Golfo Dulce. That’s four endangered species of sea turtles utilizing the embayment. Amazing!

Our biseasonal data show Golfo Dulce to be a year-round feeding and breeding area for endangered Green sea turtles. We logged over a hundred sightings of them between both surveys. This species, by far the most common, was usually observed in the upper regions of the gulf resting at the sea surface. But we also documented Green sea turtles mating in all four quadrants of the inlet, so their use of the fiord waters appears widespread.

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Marine Conservation, Science and Research

Osa Conservation Supports Research in Golfo Dulce: Photo-identification of Bottlenose dolphins

Dolphin B43 shown alongside a rendered outline of its dorsal fin. We saw this individual five times.

An unexpected but delightful result of our survey work in Golfo Dulce was the identification of about 80 individual Bottlenose dolphins (Turciops truncatus), some of which can be seen in the Appendix of my 2010 report.

How does one go about identifying dolphins? Well, pioneering biologists studying various species discovered ingenious ways to distinguish individuals. Jaguars have unique spots. Gorillas have unique nose prints. Dolphins have unique dorsal fins. By examining the shape, natural markings, scars and trailing edge, a dorsal may appear as distinct as a fingerprint. Of course dolphins don’t sit quietly at the surface while you study the intricacies of their dorsal patterns, so ID work is best done through photos. Luckily, we managed to get photographs for almost 90 percent of our dolphin sightings.

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