//
you're reading...

Book Review

Some like it hot, and that might help

Stuart-Smith, R. D., G. J. Edgar, N. S. Barrett, S. J. Kininmonth, and A. E. Bates (2015), Thermal biases and vulnerability to warming in the world’s marine fauna, Nature, doi:10.1038/nature16144.

Introduction

Over 70% of the surface of the Earth is covered by ocean. Marine environments occupy almost every latitude and exist at every temperature between freezing at the poles and almost 90°F at the equator. You might expect that every environment would have a community particularly suited to it, but it turns out that most species prefer either tropical waters or temperate waters and few like anything in the middle or anything too cold (Fig 1).

This means that many of the creatures we find living in subtropical areas may be better suited for either a colder or warmer environment. Imagine, for example, two different species of fish living in the subtropical waters off Florida. The first one can also be found living in the cooler waters of the Gulf of Maine, so Florida is on the warm end of its temperature tolerance range (Fig. 1 and Fig. 2-1). The difference between its maximum habitable temperature and the temperature of its environment is small, so this fish has a small thermal “buffer” against warming and probably won’t fare well if its environment gets any warmer. The second fish is a species suited for life in equatorial waters, so Florida falls somewhere in the middle of its temperature tolerance (Fig 1 and Fig. 2-1). This fish has a large thermal buffer and is not particularly vulnerable to warming.

Figure 1. Thermal tolerances for species living in a wide range of environments tend to fall either in tropical or temperate conditions, but not in between (typical of subtropical). Two species of fish living in an area with the same average summer sea surface temperature can have different maximum thermal tolerance (Extended Data Figure 8 in paper).

Figure 1. Thermal tolerances for species living in a wide range of environments tend to fall either in tropical or temperate conditions, but not in between (typical of subtropical). Two species of fish living in an area with the same average summer sea surface temperature can have different maximum thermal tolerance (Extended Data Figure 8 in paper).

Figure 2. Example species #1 and species #2 living in the same environment. Each species can survive in a different range of temperatures. The current temperature is near the top of the range for species #1, so the predicted warming is too much for it to handle. Species #2 has a larger thermal buffer and can tolerate the predicted warming.

Figure 2. Example species #1 and species #2 living in the same environment. Each species can survive in a different range of temperatures. The current temperature is near the top of the range for species #1, so the predicted warming is too much for it to handle. Species #2 has a larger thermal buffer and can tolerate the predicted warming.

Methods

Researchers at the Institute for Marine and Antarctic Studies in Hobart, Tasmania, used the Reef Life Survey (http://www.reeflifesurvey.com) to define the temperature tolerances of over 2,000 marine communities. First they found every fish and invertebrate species that lived in each community. For each species, they defined its thermal tolerance as the 95th percentile of the range of temperatures it was ever recorded living in. Then they averaged all the species’ thermal tolerances to define a “community thermal tolerance,” which can be thought of as the upper limit of temperatures where that community could thrive. This index describes how vulnerable the community as a whole is to warming. If the difference between the community tolerance and the current temperature is large, the community has a big “thermal buffer” against warming, but if the difference is small, the community has a small thermal buffer and is vulnerable to change.

In order to predict how marine communities will be impacted by warming, the researchers compared these thermal buffers with how temperatures are expected to change over the next hundred years.

Results

Out of 75 regions included in this analysis, 6 are expected to see rises in sea surface temperature that exceed the upper limit of more than half the species in the community by 2025 (Fig. 3, top). By 2115, a full third of regions will be too warm for 100% of their species (Fig. 3, bottom).

Figure 3. Proportion of fish and invertebrate species in present-day communities likely to exceed their upper realized thermal limit by 2025 (top) and 2115 (bottom) (Fig. 3 in paper)

Figure 3. Proportion of fish and invertebrate species in present-day communities likely to exceed their upper realized thermal limit by 2025 (top) and 2115 (bottom) (Fig. 3 in paper)

In general, communities in the mid-latitudes are most vulnerable to warming temperatures. While the mid-latitudes are not the fastest-warming areas of the ocean, the communities living here are already close to their thermal tolerances and within a few decades, the waters they inhabit will surpass their limits.

Significance

The fastest-warming regions of the world are not the only places that need our attention. Plenty of communities are already living at the edge of their thermal tolerances without much of a buffer and that’s a dangerous place to be! Even without considering the indirect consequences of warming like extreme weather events and habitat alteration, many marine communities face serious risks in the coming decades. The researchers acknowledge that this study does not consider the possibility that upper temperature limits are flexible: just because a fish hasn’t been seen in a warmer environment doesn’t mean it couldn’t do well there. Still, the analysis is eye-opening and informative. Conservation of our marine environments is an extremely important topic in ameliorating the effects of climate change, and as we consider our plans for conservation, the preservation of community structures should be a priority.

 

Discussion

Trackbacks/Pingbacks

  1. […] CO2 is a huge issue for the health of our marine resources: warming temperatures are affecting the structure and distribution of marine ecosystems, redefining where marine species like fish, crabs, and lobsters are able to live, and causing sea […]

  2. […] more in my December post on […]

Post a Comment

Instagram

  • by oceanbites 3 weeks ago
    Not all outdoor science is fieldwork. Some of the best days in the lab can be setting up experiments, especially when you get to do it outdoors. It’s an exciting mix of problem solving, precision, preparation, and teamwork. Here is
  • by oceanbites 2 months ago
    Being on a research cruise is a unique experience with the open water, 12-hour working shifts, and close quarters, but there are some familiar practices too. Here Diana is filtering seawater to gather chlorophyll for analysis, the same process on
  • by oceanbites 3 months ago
    This week for  #WriterWednesday  on  #oceanbites  we are featuring Hannah Collins  @hannahh_irene  Hannah works with marine suspension feeding bivalves and microplastics, investigating whether ingesting microplastics causes changes to the gut microbial community or gut tissues. She hopes to keep working
  • by oceanbites 3 months ago
    Leveling up - did you know that crabs have a larval phase? These are both porcelain crabs, but the one on the right is the earlier stage. It’s massive spine makes it both difficult to eat and quite conspicuous in
  • by oceanbites 3 months ago
    This week for  #WriterWednesday  on  #Oceanbites  we are featuring Cierra Braga. Cierra works ultraviolet c (UVC) to discover how this light can be used to combat biofouling, or the growth of living things, on the hulls of ships. Here, you
  • by oceanbites 3 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Elena Gadoutsis  @haysailor  These photos feature her “favorite marine research so far: From surveying tropical coral reefs, photographing dolphins and whales, and growing my own algae to expose it to different
  • by oceanbites 4 months ago
    This week for  #WriterWednesday  on Oceanbites we are featuring Eliza Oldach. According to Ellie, “I study coastal communities, and try to understand the policies and decisions and interactions and adaptations that communities use to navigate an ever-changing world. Most of
  • by oceanbites 4 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Jiwoon Park with a little photographic help from Ryan Tabata at the University of Hawaii. When asked about her research, Jiwoon wrote “Just like we need vitamins and minerals to stay
  • by oceanbites 5 months ago
    This week for  #WriterWednesday  on  #Oceanbites  we are featuring  @riley_henning  According to Riley, ”I am interested in studying small things that make a big impact in the ocean. Right now for my master's research at the University of San Diego,
  • by oceanbites 5 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Gabby Stedman. Gabby is interested in interested in understanding how many species of small-bodied animals there are in the deep-sea and where they live so we can better protect them from
  • by oceanbites 5 months ago
    This week for  #WriterWednesday  at  #Oceanbites  we are featuring Shawn Wang! Shawn is “an oceanographer that studies ocean conditions of the past. I use everything from microfossils to complex computer models to understand how climate has changed in the past
  • by oceanbites 5 months ago
    Today we are highlighting some of our awesome new authors for  #WriterWednesday  Today we have Daniel Speer! He says, “I am driven to investigate the interface of biology, chemistry, and physics, asking questions about how organisms or biological systems respond
  • by oceanbites 6 months ago
    Here at Oceanbites we love long-term datasets. So much happens in the ocean that sometimes it can be hard to tell if a trend is a part of a natural cycle or actually an anomaly, but as we gather more
  • by oceanbites 6 months ago
    Have you ever seen a lobster molt? Because lobsters have exoskeletons, every time they grow they have to climb out of their old shell, leaving them soft and vulnerable for a few days until their new shell hardens. Young, small
  • by oceanbites 7 months ago
    A lot of zooplankton are translucent, making it much easier to hide from predators. This juvenile mantis shrimp was almost impossible to spot floating in the water, but under a dissecting scope it’s features really come into view. See the
  • by oceanbites 7 months ago
    This is a clump of Dead Man’s Fingers, scientific name Codium fragile. It’s native to the Pacific Ocean and is invasive where I found it on the east coast of the US. It’s a bit velvety, and the coolest thing
  • by oceanbites 8 months ago
    You’ve probably heard of jellyfish, but have you heard of salps? These gelatinous sea creatures band together to form long chains, but they can also fall apart and will wash up onshore like tiny gemstones that squish. Have you seen
  • by oceanbites 9 months ago
    Check out what’s happening on a cool summer research cruise! On the  #neslter  summer transect cruise, we deployed a tow sled called the In Situ Icthyoplankton Imaging System. This can take pictures of gelatinous zooplankton (like jellyfish) that would be
  • by oceanbites 9 months ago
    Did you know horseshoe crabs have more than just two eyes? In these juveniles you can see another set in the middle of the shell. Check out our website to learn about some awesome horseshoe crab research.  #oceanbites   #plankton   #horseshoecrabs 
  • by oceanbites 9 months ago
    Feeling a bit flattened by the week? So are these summer flounder larvae. Fun fact: flounder larvae start out with their eyes set like normal fish, but as they grow one of their eyes migrates to meet the other and
WP2Social Auto Publish Powered By : XYZScripts.com