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Archive for the ‘Ecosystems’ Category

Creating Reefs with Tanks and Ships

Posted by Scott A. On February - 8 - 2011

Photos and article found in the February 2011 issue of National Geographic magazine, on newsstands January 25

It’s been two weeks since I found myself talking with a great crew over at the National Geographic Society.  The topic was oceans, more specifically artificial reefs, and to be honest I was begging for something to get me back in the swing of discussing our seas.  Well, 14 days later, a layover in Denver, and a swipe of the forehead for finally catching up on a backlog of graduate classes, I’m ready to engage in a little ocean diversion.

Although I have not been personally involved in the creation of artificial reefs, the idea of restoring habitat is something that I do engage in quite frequently.  And just because these restoration projects involve burrowing owls and in some cases the installation of artificial burrows, were talking about communities, ecosystems, and species.  But unlike my work in a grasslands, building artificial reefs definitely involves a stunning array of….you name it.

“Even officially sanctioned ones are often created from distinctly odd materials, including decommissioned subway cars, vintage battle tanks, armored personnel carriers, oil drilling rigs, and specially designed beehivelike modules called Reef Balls (Relics to Reefs, National Geographic Society, Feb. 2011).”

After getting past the visuals of a submerged tank or ship, there are those concerned about the impact of artificial reefs on the biodiversity of natural reefs and the potential problems of increasing overfishing.  But, I’m going to forgo jumping into that debate for the time being, and instead take a moment to share a few photos, encourage you to check out the article, and allow you to weigh the pros and cons for yourself.

Photo: David Doubilet/National Geographic

 Upholstered with luminous sponges and corals, the bridge of the U.S. Coast Guard Cutter Duane attracts schools of smallmouth grunts—and divers. The ship was intentionally sunk in 1987 off Key Largo to create an artificial reef 120 feet deep.

Photo: David Doubilet/National Geographic

 In the Flower Garden Banks National Marine Sanctuary in the Gulf of Mexico, steel pillars supporting a gas platform make a vertical reef encrusted with tube sponges.

Photo: David Doubilet/National Geographic

 This M60 is one of a hundred tanks sunk in 1994 in a 1,200-square-mile zone of artificial reefs off the coast of Alabama. The 50-ton tanks survive hurricanes better than lighter, less stable objects.

*Photos posted with permission of the National Geographic Society.

Full of Life Those Anchialine Ponds

Posted by Scott A. On June - 1 - 2010

redshrimpEver heard of an Anchialine (‘near the sea’) Pond ? Well neither had I until I stumbled upon a series of these pools adorning the coast of the Big Island of Hawaii.  While following the convex nature of the coastline from Waiulua Bay to Anaehoomalu Bay, my eyes managed to wander from the crashing waves just in time to catch a placard telling passersby to refrain from disturbing sensitive habitat.  Of course I was curious and so I left the coral beach, stepped onto the tree-shaded dirt path and peered across lava beds that were cupping crystal clear waters.  But that is an understatement as far as  a description goes because the waters bristled with life, colorful algae coated the water covered rocks and birds waded in the waters and disappeared behind once molten rock.

I was really anxious to get a closer look and for a split second even contemplated a quick inspection, but that sign flickered in my head and I knew I had to keep a responsible distance; practice what I preach whether I liked it or not.  But it did not take long to discern a path made for human travelers had been installed and provided ample space for observation.  This was virgin territory, for me anyways, and I quickly managed to forget all the signs that indicated people had come and gone before…my expedition was underway.   I traversed the well groomed path and wondered whether they were fresh or salt or brackish water ponds.  I had hypotheses for each scenario, which was extended to include a reason for the presence of an incredible amount of small fish schooling in the variety of pools ranging from the scientific units of very small to quite large.  But I began to realize their salty nature after spotting the presence of a small surgeonfish swimming amongst the other gilled residents.  Besides fish, the ponds are home for algae, plants, shrimp, snails, insects and provide foraging sites for birds.

Alas, a sign describing yet another Hawaiian treasure identified the name of my latest discovery.  And before I provide additional verbiage and photos, I should mention that I was brought back to reality as the path ultimately ended amongst the streets of civilization. An adventure none the less.

“Anchialine ponds are one of Hawaii’s most threatened ecosystems. There are about 700 known anchialine ponds in Hawai’i. Most Hawaiian anchialine ponds are in the youngest lava areas of the Big Island of Hawai’i and Maui. They exist in inland lava depressions near the shore and contain brackish (a mixture of freshwater and saltwater) water. Freshwater is fed to the ponds from ground water that moves down slope and from rainwater. Ocean water seeps into the ponds through underground crevices in the surrounding lava rock.”  University of Hawaii at Hilo

According to the signs on site, “Tiny red shrimp, collectively called ‘Opae’ula, are one of the unique features of these anchialine pools and are found only in Hawaii.  The shrimp are omnivorous and can live for long periods of time underground in the interstitial groundwater without appearing in the pools.  The shrimp have been found in wells located a mile inland.  The smaller and more numerous shrimp (Halocaridina rubra) is preyed upon by a larger red shrimp (Matabetaeus lohena).”

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Declining Parrotfish Instill Hope but Highlight Human Flaw

Posted by Scott A. On December - 1 - 2009

While rummaging through the latest research in Conservation Biology, I came across a publication that caught my attention.   It’s not that the title conveyed a trinket of enlightenment nor promised to do so as I wound my way from introduction to methods to discussion.  In fact, the title evoked an emotional response that was the exact opposite of astonishment.  And by that I merely mean I could (or assumed I could) foresee the results, which is practically a staple in the ocean conservation world when discussing the effects of a burgeoning coastal human population on neighboring marine ecosystems.  In that context, is there anything else that should pop to mind other than overfishing and declining fisheries? 

Credit: Richard Ling

But, I will admit that my curiosity was peeked as it is my first encounter with parrotfish headlining the research.  So, I decided to move forward and examine the text behind the title, “Implications of Urbanization for Artisanal Parrotfish Fisheries in the Western Solomon Islands.”  Perhaps the title’s key words like ‘urbanization’ and ‘fisheries’ are dead giveaways, but remember this is a scientific publication and not the latest thriller in the midst of protecting a multi-level plot twist for the sake of sparking revenue.

With the pages rolling it becomes quite apparent that there are a few conservation gems sprinkled throughout the paper and worthy of rehashing, or what a waste of my time in writing and yours in reading this post.   Success of marine protected areas, declining species, and the interconnectedness of species in an ecosystem are the themes/take home messages while the family Scaridae is the star, or victims, of the show. 

neg_quoteScarids, or parrotfish, included 83 species at the time of my university courses (~90 species as of 2002) and are so named because their fused teeth resemble a parrot-like beak.  And it is this beak that is quite useful for biting off pieces of coral and algal fronds.  The bits are ground down in their massive pharyngeal mills and the algal cells are extracted.  As discussed by the authors, parrotfish fill a critical role in maintaining coral reef systems by controlling filamentous algae and Scleractinian corals, removing detritus, and digging through the surface of the reef thusly redistributing the ground calcareous pieces as sediment.

As Pacific Island populations grow, the demand for coral reef resources including the parrotfishes themselves increases dramatically.  Thus, it is not surprising that the fishing pressures have caused a total parrotfish population decline of 45% from 2004 to 2005 in the Pacific Island study area. But remember I said there were a few conservation gems…well it turns out communities in the Western Solomon Islands have begun to see the frightening trends and instituted management practices and community-based marine protected areas to curb the overfishing (and habitat degradation) problem.  Not only are their livelihoods on the line but the whole coral reef system.

The take home lesson is that community-based marine protected areas do in fact work, and is evident with the following results:

 -Parrotfish numbers/abundance in outside sites were significantly lower than inside community-based marine protected areas (CBMPA) for each size category.

-Large effects between inside and outside CBMPAs were evident in each size category.

-Combined, these findings reinforce the stark difference in abundance across fish size categories between inside and outside the CBMPAs of villages with customary management and an urbanized center.

Photo: Richard Ling

We now have yet another piece of evidence highlighting the need for marine protected areas to ensure healthy fish populations and coral reefs, as well as a need to conserve for the future health of a growing human population.  However, instilling good ocean management practices is not and an idea we can afford to treat with procrastination.  According to the authors, “There is a negative correlation between effective conservation and human population size (beyond a threshold of more than 1000 people) and between market integration and wealth, which suggests that as rural communities urbanize and monetize in Melanesia, their capacity to conserve resources weakens.”

And this negative correlation is perhaps the most interesting finding and something that sounds quite familiar.  As populations grow and become more economically viable they effectively lose their ecological self-control and ocean husbandry suffers. 

So is this humankind’s innate progression as we become less reliant on the natural course of the environment and aim to control it?  I have definitely seen this trend before…Have you?

This post was chosen as an Editor's Selection for ResearchBlogging.org
ASWANI, S., & SABETIAN, A. (2009). Implications of Urbanization for Artisanal Parrotfish Fisheries in the Western Solomon Islands Conservation Biology DOI: 10.1111/j.1523-1739.2009.01377.x
Photo credits: Richard Ling

Good news and threats for Monterey Bay health

Posted by Scott A. On October - 2 - 2009

kelp forestIt’s Friday…So let’s keep this week’s trend of good news coming for ocean conservation.  The Monterey Bay National Marine Sanctuary received relatively good overall health ratings in NOAA’s latest report.  However, the typical issues afflicting all our coasts are no stranger nor any less of a threat to this valuable marine sanctuary.

[The Report] indicates that the overall condition of the sanctuary’s marine life and habitat ranges from good (highest rating) to fair (moderate rating), but identifies several threats to sanctuary resources, such as growing coastal populations, agricultural and urban runoff, vessel traffic and marine debris.

“The sanctuary was designated because of its extraordinary resources and qualities, and this report confirms its continued vitality,” said Paul Michel, Monterey Bay National Marine Sanctuary superintendent. “But it also reveals that expanding human population and activities require adaptive management strategies to preserve the sanctuary today and into the future.”

Offshore and nearshore environments are generally rated in the report as good (highest rating) to fair (moderate rating). In the nearshore, habitat-forming plants and animals, such as surfgrass, kelp and sponges, are healthy, according to the report. However, rockfish, salmon, and some seabird and marine mammal species have declined.

Proximity to dense population centers and agriculture is a factor in nearshore water quality. The boundary of Monterey Bay National Marine Sanctuary reaches to the shoreline for 276 miles along California’s coast. Beach water quality issues that are common throughout California, such as elevated pollutant levels, are also observed within the sanctuary.

The report also reflects a fair to poor rating for water quality, habitat and living resources in the estuarine environment of Elkhorn Slough, a part of the sanctuary. The sanctuary has already partnered with multiple agencies to implement strategies to restore estuarine habitats and improve water quality and the health of plants and animals in Elkhorn Slough.Harbor Seal

Emerging or poorly understood threats present new challenges to sanctuary resources. Global climate change is already impacting ocean chemistry, which is expected to affect marine biodiversity and biological productivity. Habitat quality and living resource conditions are impacted by pollutants, marine debris, changing ocean conditions and disease. Rising population growth in adjacent cities and counties, vessel traffic, as well as air and water pollution from outside the sanctuary’s boundaries are also a concern. New management strategies will be necessary to meet some of these emerging resource threats.



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