From the department of obvious science and anything to do with climate change must be bad comes this study from Australian National University:
Waves costly for fish
Big waves are energetically costly for fish, and there are more big waves than ever. The good news is that fish might be able to adapt.
“There has been a lot of recent work in oceanography documenting the fact that waves are becoming more frequent and more intense due to climate change,” says Mr Dominique Roche, PhD candidate from the Research School of Biology. “The habitats that fish live in are changing.”
“This is not a localised problem, but something that is documented globally,” adds Ms Sandra Binning, also a PhD candidate in the Research School of Biology.
Mr Roche and Ms Binning are co-authors on a study documenting the energy it takes for fish to swim through large, intense waves. Specifically, they focused on fish that swim with their arm, or pectoral fins, which are very common on both rocky and coral reefs.
“By controlling water flow in an experimental chamber with the help of a computer, we were able to replicate oscillations in the water flow like in a wave pool,” explains Mr Roche.
“We looked at how much energy the fish consumed while swimming without waves, in conditions with small waves, and in conditions with large waves. The idea was to compare the amount of energy that fish consume while swimming in these three conditions when their average swimming speed was exactly the same.”
Mr Roche and Ms Binning found that it’s a lot more energetically demanding for fish to deal with large fluctuations in water speed and wave height.
“It’s harder to constantly switch speeds than it is to remain at a constant speed, like a runner changing between running and walking during interval training versus a steady jog. Well, it’s the same for swimming fish,” says Mr Roche.
“Things could get tough for fish in windy, exposed habitats if waves get stronger with changing climate. But there may be a silver lining,” says Ms Binning.
“In the swim chamber, when the water flow increased, fish had to beat their fins faster to keep up. But when the water flow slowed down, some fish took advantage and rode the wave. Essentially, rather than beating their fins frantically, these fish used the momentum that they had gained while speeding up to glide and save energy.
“This means that some individuals are better at dealing with waves than others, and that there is hope for populations to adapt their swimming behavior to potentially changing conditions in the future,” concludes Mr Roche.
Gosh, climate change will cause exhausted fish in the future, because as we all know, fish just can’t adapt to a changing environment; nature so poorly equipped them that something like a change in waves in the ocean will just muck up the whole population, because fish just can’t swim deeper to avoid surface turbulence, or something.
And, because this one species of fish is surely representative of all species and good enough to make a climate change with global ramifications related press release out of. Never mind this fact:
The shiner perch (Cymatogaster aggregata) is a common surfperch found in estuaries, lagoons, and coastal streams along the Pacific coast from Alaska to Baja California. It is the sole member of its genus.
They are one of the most common fish in the bays and estuaries of their range, favoring beds of eelgrass, and often accumulating around piers as well. They feed on zooplankton such as copepods, but have been observed to bottom feed as well.
Cuz, well, the bays and estuaries are connected to the ocean, and the ocean has waves, and they are getting bigger. And because, somehow, a bottom fish will be more affected by waves on the surface.
I downloaded the footage of the study species, Cymatogaster aggregata in the swim chamber, and have made it available here:
This is what passes for science now; it looks like a high school science fair project. Note the propeller. What I see is the velocity of water changing due to the propeller, an enclosed box, and no waves, i.e. an unnatural environment. As Willis is often fond of pointing out, an aquarium tank is not the ocean, and behavior of an animal in an artificially controlled setting is no guarantee it models reality, even in the slightest. This doesn’t even look like a good model, because the fish is movement constricted, and can’t change its depth.
I assume they are basing their work on this study, also from Australian National University:
Global Trends in Wind Speed and Wave Height
Science, Vol. 332 no. 6028 pp. 451-455 DOI: 10.1126/science.1197219
- I. R. Young*, S. Zieger, A. V. Babanin
*To whom correspondence should be addressed. E-mail: email@example.com
Studies of climate change typically consider measurements or predictions of temperature over extended periods of time. Climate, however, is much more than temperature. Over the oceans, changes in wind speed and the surface gravity waves generated by such winds play an important role. We used a 23-year database of calibrated and validated satellite altimeter measurements to investigate global changes in oceanic wind speed and wave height over this period. We find a general global trend of increasing values of wind speed and, to a lesser degree, wave height, over this period. The rate of increase is greater for extreme events as compared to the mean condition.
Then there’s this little gem in the paper:
That paper is contested on the basis of that table:
Comment on “Global Trends in Wind Speed and Wave Height”
Frank J. Wentz*, Lucrezia Ricciardulli
Young et al. (Reports, 22 April 2011, p. 451) reported trends in global mean wind speed much larger than found by other investigators. Their report fails to reference these other investigations and does not discuss the consequences that such large wind trends would have on global evaporation and precipitation. The difference between their altimeter and buoy trends suggests a relatively large trend error.
Of course this new paper on waves make fish swim harder [Unsteady flow affects swimming energetics in a labriform fish (Cymatogaster aggregata) ] from ANU is published in the same journal (Journal of Experimental Biology) that says ocean acidification will make damselfish go blind: Ocean acidification will interfere with fish eyes
But what I find most interesting is that the original abstract doesn’t even MENTION climate change:
Unsteady flow affects swimming energetics in a labriform fish (Cymatogaster aggregata)
Unsteady water flows are common in nature, yet the swimming performance of fishes is typically evaluated at constant, steady speeds in the laboratory. We examined how cyclic changes in water flow velocity affect the swimming performance and energetics of a labriform swimmer, the shiner surfperch, Cymatogaster aggregata, during station holding. Using intermittent-flow respirometry, we measured critical swimming speed (Ucrit), oxygen consumption rates (ṀO2) and pectoral fin use in steady flow versus unsteady flows with either low- [0.5 body lengths (BL) s−1] or high-amplitude (1.0 BL s−1) velocity fluctuations, with a 5 s period. Individuals in low-amplitude unsteady flow performed as well as fish in steady flow. However, swimming costs in high-amplitude unsteady flow were on average 25.3% higher than in steady flow and 14.2% higher than estimated values obtained from simulations based on the non-linear relationship between swimming speed and oxygen consumption rate in steady flow. Time-averaged pectoral fin use (fin-beat frequency measured over 300 s) was similar among treatments. However, measures of instantaneous fin use (fin-beat period) and body movement in high-amplitude unsteady flow indicate that individuals with greater variation in the duration of their fin beats were better at holding station and consumed less oxygen than fish with low variation in fin-beat period. These results suggest that the costs of swimming in unsteady flows are context dependent in labriform swimmers, and may be influenced by individual differences in the ability of fishes to adjust their fin beats to the flow environment.
So, maybe the whole climate change meme is an addition for the purposes of press release, to gain attention, either way, it all seems fishy to me.