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Declining Parrotfish Instill Hope but Highlight Human Flaw

Posted by Mola2mola 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

Reef Triggerfish Displays Territoriality

Posted by Mola2mola On November - 25 - 2009

Humuhumunukunukuapua’a (or reef triggerfish) shows me who’s the ocean boss in just 10 seconds.  Well, boss over this section of a reef in Maui at any rate.  After 10 seconds I decided to leave him in peace to guard his territory.

Exploring the reefs of Hawaii

Posted by Mola2mola On August - 14 - 2009

An eternity, perhaps not quite, but that’s my perception of time when thinking back to my Hawaiian excursion in mid-June.  And finishing up a home movie chronicling our adventure, complete with contemporary Island music from the likes IZ for instance, just gets me in the mood for some white sandy beaches and clear salty waters.  So why not share a few things I came across while swimming over the reefs of Maui.

Obviously such a post lends itself infinity as the amount of pictures and video I have is substantial… notice I did not mention anything about quality.  But with that said, using a digital underwater camera is  a goldmine for someone who needs to cull through the blurs to find a few gems. 

Of course I need to start the ball rolling with a Hawaiian green sea turtle.  It is by far my wife’s favorite marine creature and I am always left in awe at the range of colors found on their carapace.  By the way, did you see our Hawaiian green sea turtle video footage?  And even in today’s world of rampant conservation information,  I was left in shock to discover people clamoring to touch and harass this amazing species (And yes members of our party spoke up immediately to inform the culprits and end their activities). I guess that’s why we need to continue spreading the word.

 

Hawaiian Green Sea Turtle

Hawaiian Green Sea Turtle

 

Yellowtail coris (juvenile)

A juvenile yellowtail coris (Coris gaimard), which is the first one I have run across in Hawaii

 

Raccoon butterflyfish

A raccoon butterflyfish (Chaetodon lunula)

 

Sea urchins

A Slate or Red pencil urchin (Heterocentrotus mammillatus) and a black sea urchin (Echinothrix diadema)

 

Cushion seastar

A cushion seastar (Culcita novaeguineae)

 

Whitemouth morray eel

Whitemouth moray eel (Gymnothorax meleagris)

 

Arc-eye hawkfish

An Arc-eye hawkfish (Paracirrhites arcatus)

 

Octopus and bird wrasse

The Hawaiian Day Octopus (Octopus cyanea) and a female bird wrasse (Gomphosus varius)

Coral bleaching and macroalgae infiltration

Posted by Mola2mola On May - 27 - 2009

Coral decline“In 2004, visual estimates of mortality and algal overgrowth of Montipora capi¬tata and M. cf. turgescens at back reef sites at the three northern atolls conservatively exceeded 50%, with nearly complete mortality of surface-facing portions of colonies at numerous sites. The shallow crest of a large central patch reef system at Kure Atoll, previously referred to as “the coral gardens” due to its luxuriant growth of montiporids and pocilloporids, was heavily bleached in 2002. In 2004, only a few branches of Porites com¬pressa remained alive and the dead coral skeletons were thickly covered in turf and macroalgae.”

 

Reference:

Friedlander, A., K. Keller, L. Wedding, A. Clarke, M. Monaco (eds.). 2009. A Marine Biogeographic Assessment of the Northwestern Hawaiian Islands. NOAA Technical Memorandum NOS NCCOS 84. Prepared by NCCOS’s Biogeography Branch in cooperation with the Office of National Marine Sanctuaries Papahanaumokuakea Marine National Monument. Silver Spring, MD. 363 pp.

Photos: J. Kenyon.


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