Ryan just published a paper in Ecology Letters showing that the number of species in many parts of the coastal ocean is going up, not down as many would expect. He spent the past few years trying to understand how marine biodiversity is changing, but his findings were initially so surprising that he doubted them.
Globally, biodiversity is going down. But because some species have started to live in more places, and different places, what happens globally isn’t what we see locally.
He studied decades of patterns in biodiversity around the North American coastline, and surprisingly, most of these regions show *increases* in the number of species present. At the same time, He found that organisms that were previously rare in these areas are becoming increasingly common.
Jordan Holtswarth joined our lab last summer as an REU student and did a wonderful job analyzing photos we had on clownfish reproduction in Leyte, Philippines. Her paper showing they breed November-May (the cold months) is just out in Bulletin of Marine Science.
Jim’s paper on rapid responses of marine animals to winter temperature variability is now out in Global Change Biology. He found strong variation in how animals responded to a warm winter (higher or lower abundance; or shift north vs. south), but the rate and direction of response was predictable from thermal affinity.
Ryan has been hard at work to understand long-term trends in species richness in marine ecosystems all around North America. The paper was just accepted in Ecology Letters! More on this later.
Jordan Holtswarth was an REU student in our lab last summer, and her paper on reproduction in clownfish is now in press at Bulletin of Marine Science!
Our new paper on extinction risk in marine and terrestrial species is out today in PNAS, “Range contraction enables harvesting to extinction” [free preprint here]. Led by Matthew Burgess at UCSB, the research shows that shrinking distributions puts many animals at further risk from extinction as their abundance decline. While harvesters (fishers or hunters) are typically expected to stop harvesting when a species becomes rare and the costs of harvest become too high, contraction of a species into dense clusters can keep harvesting profitable, even at very low abundance. Examples of species with these contractions include Bengal tigers, Asian elephants, and bluefin tunas.
It is tempting to try to guess which species will be the winners of climate change, and which the losers. But our new paper in Trends in Ecology and Evolution suggests that we should avoid doing that when we design management and conservation measures. Instead, we propose harnessing the diversity and evolutionary capacity of the natural world as a climate adaptation strategy by designing “adaptation networks.” We focus on coral reefs as a particularly salient example.
Baby fish float on ocean currents. So where do they go? Our paper out this week in Current Biology uses DNA to answer that question for clownfish in Papua New Guinea, and about 20 km is the simple answer. What’s especially exciting is that we show how very common and easily measured population genetic patterns called “isolation by distance” accurately measure the larval dispersal process. We validated our answer against observations of dispersal for hundreds of individual larvae (an incredibly time-consuming endeavor). Our findings help open the door to applying the isolation by distance method to a much wider range of marine species.
This work was the result of an exciting collaboration with Serge Planes, Geoff Jones, Simon Thorrold, Pablo Saenz-Agudelo, Michael Berumen, Michael Bode, and others.
Jim Morley has a new paper just online early in Global Change Biology (here). Studying marine fish and invertebrates of the coast of the southeast US, he found that winter temperatures quickly and predictably affect species’ distribution and abundance in the following year. In particular, we found a greater abundance of southern, warm-water species following mild winters. We also found that these impacts cascade up to affect fisheries catches for many species. Interestingly, these responses appear in a region that has not been warming over the last couple decades, though 1-3 °C of warming is expected by the end of this century. Warmer winters likely will result in increased abundance of species with more southern affinities, such as white and pink shrimp, southern hake, and star drum.
With a great set of co-authors, including Eli Fenichel at Yale, we just published a paper in Nature Climate Change showing how to measure the impacts of climate change on wealth. Our previous work, including this, has shown how climate pushes natural resources around. In this new paper, we show that those movements change who gets access to resources, and how those movements affect wealth. As important, or even more important, than the quantity of resources, however, is the quality of a region’s resource management, existing institutions, and fishing regulations. Places with strong resource management stand to gain the most from climate-driven changes in resource distribution.
To make these points, we use a hypothetical example with two fishing ports.
This is one of the initial publications from our NSF Coastal SEES grant examining the impacts of climate change on fish and fisheries.
This figure shows three of the key sources of uncertainty in any projection, using sea surface temperature as an example: the model used to make the projection (blue), the climate change scenario followed (green), and irreducible variability in the model (orange). The graph shows how natural variability dominates over the next couple decades, but the scenario of greenhouse gas emissions is very important by the end of the century.