Cartoon guide to biodiversity loss LI

23 10 2018

The six set of six biodiversity cartoons for 2018. See full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here.


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Cartoon guide to biodiversity loss L

3 08 2018

The fifth set of six biodiversity cartoons for 2018. See full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here.


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Cartoon guide to biodiversity loss XLIX

2 07 2018

The fourth set of six biodiversity cartoons for 2018. See full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here.


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Communicating climate change

5 06 2018

Both the uncertainty inherent in scientific data, and the honesty of those scientists who report such data to any given audience, can sow doubt about the science of climate change. The perception of this duality is engrained in how the human mind works. We illustrate this through a personal experience connecting with global environmentalism, and synthesise some guidelines to communicate the science of climate disruption by humans.

EskimoTote_English

Courtesy of Toté (www.elcomic.es)

In January 2017, the Spanish environmental magazine Quercus invited us to give a talk, at the Cabinet of Natural History in Madrid, about our article on the effects of climate change on the feeding ecology of polar bears, which made to Quercuscover in February 2017 (1) — see blog post here. During questions and debate with the audience (comprising both scientists and non-scientists), we displayed a graph illustrating combinations of seven sources of energy (coal, water, gas, nuclear, biomass, sun and wind) necessary to meet human society’s global energy needs according to Barry Brook & Corey Bradshaw (2). That paper supports the idea that nuclear energy, and to a lesser extent wind energy, offer the best cost-benefit ratios for the conservation of biodiversity after accounting for factors intimately related to energy production, such as land use, waste and climate change.

While discussing this scientific result, one member of the audience made the blunt statement that it was normal that a couple of Australian researchers supported nuclear energy since Australia hosts the largest uranium reservoirs worldwide (~1/3 of the total). The collective membership of Quercus and the Cabinet of Natural History is not suspicious of lack of awareness of environmental problems, but a different matter is that individuals can of course evaluate a piece of information through his/her own and legitimate perspective.

The stigma of hypocrisy

Indeed, when we humans receive and assimilate a piece of information, our (often not self-conscious) approach can range from focusing on the data being presented to questioning potential hidden agendas by the informer. However, the latter can lead to a psychological trap that has been assessed recently (3) — see simple-language summary of that assessment in The New York Times. In one of five experiments, a total of 451 respondents were asked to rank their opinion about four consecutive vignettes tracking the conversation between two hypothetical individuals (Becky & Amanda) who had a common friend. During this conversation, Amanda states that their friend is pirating music from the Internet, and Becky (who also illegally downloads music) can hypothetically give three alternative answers: Read the rest of this entry »





Cartoon guide to biodiversity loss XLVIII

26 04 2018

The third set of six biodiversity cartoons for 2018. See full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here.


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Penguins cheated by ecosystem change

13 03 2018

Jorge Drexler sings “… I was committed not to see what I saw, but sometimes life is more complex than what it looks like …”*. This excerpt by the Oscar-winning Uruguayan singer seems to foretell the theme of this blog: how the ecological complexity of marine ecosystems can elicit false signals to their predators. Indeed, the fidelity of marine predators to certain feeding areas can turn demographically detrimental to themselves when the amount of available food shrinks. A study of jackass penguins illustrates the phenomenon in a context of overfishing and ocean warming.

CB_JackassPenguinsEcologicalTrapPhoto

Adult of jackass penguin (Spheniscus demersus) from Robben Island (South Africa) — in the inset, one of the first juveniles released with a satellite transmitter on its back. The species is ‘Endangered’ under IUCN’s criteria (28), following a recent halving of the total population currently estimated at ~ 80,000 adults. Jackass penguins are the only penguins living in Africa, and owe their common name to their vocalisations (you can hear their braying sounds here); adults are ~ 50 cm tall and weigh ~ 3 kg. Photos courtesy of Richard Sherley.

Surface temperature, dissolved oxygen, acidity and primary productivity are, by and large, the top four environmental factors driving the functionality of marine ecosystems (1). Growing scientific evidence supports the idea that anthropogenic warming of the atmosphere and the oceans correlates with this quartet (2). For instance, marine primary productivity is enhanced by increased temperatures (3), but a warmer sea surface intensifies stratification, i.e., stacked layers of seawater with contrasting physical and chemical properties.

In coastal areas experiencing ‘upwelling’ (where winds displace surface water, allowing deep water laden with nutrients to reach the euphotic zone where plankton communities feast), stratification weakens upwelling currents and, in turn, limits the growth of plankton (4) that fuels the entire trophic web, including our fisheries. The study of these complex trophic cascades is particularly cumbersome from the perspective of large marine predators because of their capacity to move long distances, from hundreds to thousands of kilometres (5), with strong implications for their conservation (6).

With those caveats in mind, Richard Sherley and colleagues satellite-tracked the movement of 54 post-fledged, juvenile jackass penguins (Spheniscus demersus) for 2-3 years (7). All individuals had been hatched in eight colonies (accounting for 80% of the global population), and were equipped with platform terminal transmitters. Jackass penguins currently nest in 28 island and mainland locations between South Africa and Namibia. Juveniles swim up to 2000 km in search of food and, when approaching adulthood, return to their native colonies where they reproduce and reside for the remainder of their lives (watch individuals swimming here).

The natural history of this species is linked to the Southern Hemisphere’s trade winds (‘alisios’ for Spanish speakers), which blow from the southeast to the tropics. In the South Atlantic, trade winds sustain the Benguela Current, the waters of which surface from some 300 m of depth and fertilise the marine ecosystems stretching from the Western coasts of South Africa to Angola (8). Read the rest of this entry »





Cartoon guide to biodiversity loss XLVII

7 03 2018

The next set of six five biodiversity cartoons for 2018. See full stock of previous ‘Cartoon guide to biodiversity loss’ compendia here.

 

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