Heather Welch’s new paper in Nature Communications highlights the difficult road ahead in terms of managing for marine heatwave impacts on top predator species. Another new paper by Alexa Fredston found marine heatwaves were not a dominant driver of demersal fish biomass which begs the question, why not?
I took a whale picture once on Stellwagen Bank National Marine Sanctuary. It was a pretty cool picture. It’s a forever stamp now!
Read more about the story behind the picture at NOAA Fisheries, from when I was a young researcher.
Researchers have developed global forecasts that can provide up to a year’s advance notice of marine heatwaves, sudden and pronounced increases in ocean temperatures that can dramatically affect ocean ecosystems.
“We have seen marine heatwaves cause sudden and pronounced changes in ocean ecosystems around the world, and forecasts can help us anticipate what may be coming,” said lead author Michael Jacox, a research scientist at NOAA Fisheries’ Southwest Fisheries Science Center in Monterey, California, and NOAA’s Physical Sciences Laboratory in Boulder, Colorado.
Marine heatwave forecasts will be available online through NOAA’s Physical Sciences Laboratory. The researchers called the forecasts a “key advance toward improved climate adaptation and resilience for marine-dependent communities around the globe.”
M.G. Jacox, M.A. Alexander, D. Amaya, E. Becker, S.J. Bogard, S. Brodie, E.L. Hazen, M. Pozo Buil, and D. Tommasi, 2022. Global seasonal forecasts of marine heatwaves. Nature 604, 486–490. PDF
Read the abstract of the paper below:
Infographic (c) Stephanie Brodie
From 1910 to 1970, humans killed an estimated 1.5 million baleen whales in the frigid water encircling Antarctica. They were hunted for their blubber, baleen – the filtering fringe they have in place of teeth – and meat. One might assume that from the perspective of krill – the tiny shrimp-like creatures the whales feast on – this would be a boon. Yet the krill are at a fraction of their historical biomass.
With these new consumption estimates, the researchers calculated that the early 20th- century abundance of krill in the Southern Ocean was about five times what it is now in order to feed the pre-whaling whale population. This implies a complex role for whales in their ecosystems where the decline or recovery of their populations is strongly tied to overall ecosystem productivity and functioning.
Figure 1. Fieldwork needed to measure whale size, behavior, and the density of the prey they eat. The vertical difference in foraging and feces may redistribute nutrients to keep marine ecosystems flowing.
Where do animals go is not always where animals find food. Using heat increment of feeding, which is the integrated energy from a gulp of food, we can look at not just where animals go but also where they have success in feeding. Shifting distributions in anomalous years may both optimize the physiology and the feeding of these iconic and threatened species.
Our paper was published today (2/9/2021) in Global Change Biology titled “Plastic ingestion by marine fish is widespread and increasing.” Rather than starting from scratch, I include an excerpt below from the Conversation piece written by Alex McInturf and Matt Savoca,
“Trillions of barely visible pieces of plastic are floating in the world’s oceans, from surface waters to the deep seas. These particles, known as microplastics, typically form when larger plastic objects such as shopping bags and food containers break down.
Researchers are concerned about microplastics because they are minuscule, widely distributed and easy for wildlife to consume, accidentally or intentionally. We study marine science and animal behavior, and wanted to understand the scale of this problem. In a newly published study that we conducted with ecologist Elliott Hazen, we examined how marine fish – including species consumed by humans – are ingesting synthetic particles of all sizes.”
Savoca, A. McInturf, E.L. Hazen, 2021. Plastic ingestion by marine fish is widespread and increasing. Global Change Biology. DOI: 10.1111/gcb.15533. PDF
A recent review from our group at ERD highlights the ability for highly mobile predators to serve a role as ecosystem sentinels, by integrating the ocean processes around them, and telling us something we would not otherwise know about the oceanic ecosystems. In an ideal world, we’d have fine scale measurements of the ecosystem components and thresholds that result in change, but top predators respond in multiple scales, from changes in breeding success, movement patterns, to diet analyses we can understand more about ocean ecosystems and when changes are likely to occur. We hope this manuscript will both further the discussion of the roles of top predators in the global ocean observing system, but also as sentinels for rapid response, when ecosystem changes are likely to occur, and when adaptive management will be most needed.
E.L. Hazen, B. Abrahms, S. Brodie, G. Carroll, M. Jacox, M.S. Savoca, K.L. Scales, W.J. Sydeman, and S.J. Bograd, 2019. Marine Top Predators as Climate and Ecosystem Sentinels. Frontiers in Ecology and the Environment. DOI: 10.1002/fee.2125 PDF
Climate variability and change can result in ecosystem response via trophic pathways. Trophic linkages (gray and colored arrows) are represented in a generic pelagic food web. Solid colored lines represent a direct relationship between a sentinel via the metric measured and an ecosystem component; dashed colored lines represent the capacity of an organism to function as a leading sentinel, which can be used to predict a future ecosystem response; and dotted colored arrows represent the ecosystem link that is heralded by a leading sentinel.
A new paper by Heather Welch titled “Decision support tools for dynamic management” in Conservation Biology highlights the role of decision support tools when integrating multiple species distribution models into a management tool. For example, the question being asked is critically important in the tool design. The algebraic formulation for EcoCast, is highly relative and scales geometrically while Marxan can have exponential relationships because of the algorithm used to ensure a certain percentage of habitat is ultimately protected. It is another good example of where there is no one size fits all approach towards tool building for multiple management goals.
Figure 3. Effect of changing management priorities for leatherback turtles and swordfish on EcoCast (top row) and Marxan (bottom row) tool outputs relative to species habitat suitability. Curves show generalized additive models fit to each weighting run.
Dr. Brodie’s new paper reveals trade-offs in species distribution modeling between accurately estimating species abundance, spatial patterns, and underlying species~environment relationships. The short answer, is there is no one best tool and choosing the right tool depends on your modeling goals. I still refer frequently to Elith et al. 2006 as a good lesson on which models are best reproducing spatial patterning, but Steph’s paper highlights that pattern is only part of the process, particularly when modeling for fisheries management.
With the advent of WhaleWatch, we knew that monthly predictions and 0.25° were too coarse to inform fine scale management decisions yet that was the best we could do with the environmental data we had available. In two short years, we have now updated the model to an ensemble of multiple modeling approaches, and moved from predictions using satellite data to higher resolution ocean model output (daily and 0.10 °). Briana also used a thorough dataset of independent data to check the model’s accuracy and found very good performance, particularly during the peak of whale migration. Improving and assessing the accuracy of operational tools is a necessity, but one that we would not have been able to accomplish without support from the Benioff Ocean Initiative.
B. Abrahms, H. Welch, S. Brodie, M.G. Jacox, E.A. Becker, S.J. Bograd, L.M. Irvine, D.M. Palacios, B.R. Mate, and E.L. Hazen, 2019. Dynamic ensemble models to predict distributions and anthropogenic risk exposure for highly mobile species. Diversity and Distributions. doi.org/10.1111/ddi.12940 PDF
