It’s not all about temperature for corals

31 05 2017

CB_ClimateChange6_Photo

Three of the coral species studied by Muir (2): (a) Acropora pichoni: Pohnpei Island, Pacific Ocean — deep-water species/IUCN ‘Near threatened’; (b) Acropora divaricate: Maldives, Indian ocean — mid-water species/IUCN ‘Near threatened’; and (c) Acropora gemmifera: Orpheus Island, Australia — shallow-water species/IUCN ‘Least Concern’. The IUCN states that the 3 species are vulnerable to climate change (acidification, temperature extremes) and demographic booms of the invading predator, the crown-of-thorns starfish Acanthaster planci. Photos courtesy of Paul Muir.

Global warming of the atmosphere and the oceans is modifying the distribution of many plants and animals. However, marine species are bound to face non-thermal barriers that might preclude their dispersal over wide stretches of the sea. Sunlight is one of those invisible obstacles for corals from the Indian and Pacific Oceans.

If we were offered a sumptuous job overseas, our professional success in an unknown place could be limited by factors like cultural or linguistic differences that have nothing to do with our work experience or expertise. If we translate this situation into biodiversity terms, one of the best-documented effects of global warming is the gradual dispersal of species tracking their native temperatures from the tropics to the poles (1). However, as dispersal progresses, many species encounter environmental barriers that are not physical (e.g., a high mountain or a wide river), and whose magnitude could be unrelated to ambient temperatures. Such invisible obstacles can prevent the establishment of pioneer populations away from the source.

Corals are ideal organisms to study this phenomenon because their life cycle is tightly geared to multiple environmental drivers (see ReefBase: Global Information System for Coral Reefs). Indeed, the growth of a coral’s exoskeleton relies on symbiotic zooxanthellae (see video and presentation), a kind of microscopic algae (Dinoflagellata) whose photosynthetic activity is regulated by sea temperature, photoperiod and dissolved calcium in the form of aragonite, among other factors.

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Limited nursery replenishment in coral reefs

27 03 2017
Haemulon sciurus

blue-striped grunt (Haemulon sciurus)

Coral reef fishes are wonderfully diverse in size, form, and function, as well as their need for different habitats throughout the life cycle. Some species spend all of their life in the same kind of coral habitat, while others need different places to breed and feed.

Fishes requiring different habitats as they progress through life often have what we call ‘nurseries’ in which adults lay eggs and the subsequent juveniles remain, and these places are often dominated by mangroves or seagrasses (i.e., they are not part of the coral reef).

While we’ve known for quite some time that when these nursery habitats are not around, adjacent coral reefs have few, if any, of these nursery-dependent species. What we haven’t known until now is just how far the influence of nurseries extends along a coral reef.

In other words, if a nursery is present, just how many new recruits do different areas of a reef receive from it? Read the rest of this entry »





Influential conservation ecology papers of 2016

16 12 2016

cheetah_shutterstock_37268149As I have done for the last three years (2015, 2014, 2013), here’s another retrospective list of the top 20 influential conservation papers of 2016 as assessed by experts in F1000 Prime.

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Influential conservation papers of 2015

25 12 2015

most popularAs I did last year and the year before, here’s another arbitrary, retrospective list of the top 20 influential conservation papers of 2015 as assessed via F1000 Prime.

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Cartoon guide to biodiversity loss XXVIII

4 02 2015

First batch of six biodiversity cartoons for 2015 (see full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here).

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Influential conservation papers of 2014

22 12 2014

splash2Another year, another arbitrary retrospective list – but I’m still going to do it. Based on the popularity of last year’s retrospective list of influential conservation papers as assessed through F1000 Prime, here are 20 conservation papers published in 2014 that impressed the Faculty members.

Once again for copyright reasons, I can’t give the whole text but I’ve given the links to the F1000 assessments (if you’re a subscriber) and of course, to the papers themselves. I did not order these based on any particular criterion.

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Interview with a social (conservation) scientist

22 06 2010

I was contacted recently by Josh Cinner, a self-titled ‘social’ scientist (now working at the Centre of Excellence for Coral Reef Studies) who has published rather a lot in the conservation literature. He was recently highlighted in the journal Science for his work, and he thought CB readers would enjoy the coverage. He stated to me:

“…as a social scientist, I have spent the past decade or so working with ecologists and managers trying to integrate social science better in conservation. There are often calls for the importance of integrating social science in conservation and I thought your blog readers might appreciate some high-level recognition of the importance of this. Additionally, as far as I can tell, this is the first of these profiles that has focused on someone working in conservation.”

So, while fully crediting the source of this article and its author, Helen Fields, here is the entire text reproduced for your reading pleasure.

In the late 1980s, things were not going well for the coral reefs at Jamaica’s Montego Bay Marine Park. Overfishing had taken out a lot of the fish that eat algae, and algae were taking over the reef. “It was a classic case of ecosystem decline,” human geographer Joshua Cinner says. He arrived in Jamaica in 1996 as a Peace Corps volunteer after graduating from the University of Colorado, Boulder, with a double major in environmental conservation and geography. He was particularly interested in parks and preserves.

He’d landed in the middle of a war. Lobbying by tour operators and others got spearfishing, one of the main culprits in overfishing, banned in the park. The ban did not go over well with local people. “All the park equipment got vandalized. We had park rangers get threatened; their families got threatened at spear point,” Cinner says. Spearfishing equipment is cheap and you don’t need a boat; men who do it are generally poor and are fishing as a last resort. “The cultural lens through which the fishermen viewed this issue was of struggle in a post-slavery society, of the rich, predominantly white expatriates making a law that oppressed the poorest of the poor locals to benefit the wealthy.”

The conflict got Cinner thinking about how conservation really works. “It wasn’t really about the ecology,” he says. “Making conservation work in Jamaica had a lot to do with understanding the local culture and people.” It also opened his eyes to the role oceans play. “The ocean is often viewed as an open-access resource. That extra layer of complexity interested me,” he says. “Land can often be private property,” but “the ocean is typically viewed as free for anyone to fish in, for anyone to swim in and use.” Read the rest of this entry »