//
you're reading...

Biology

Can being sick be a good thing for surviving ocean acidification?

Paper: MacLeod CD, Poulin R (2016) Parasitic infection: a buffer against ocean acidification? Biol Lett 12

Introduction

With climate change, increased levels of carbon dioxide (CO2) in the atmosphere is dissolving into the oceans, lowering their overall pH and making it more acidic, a process termed ocean acidification (OA). Oceanbites writers (including yours truly) have posted a great deal of articles on ocean acidification, mostly because it’s such a hot topic in the marine research world right now. It’s vital to our shellfisheries and conservation efforts that we understand the effects of ocean acidification on animals. There are a bunch of published papers documenting what happens when you put a specific animal, like yellowfin tuna, lobsters, and sea urchins in more acidic water.

However, in the real world, an animal rarely contends with just low pH. The water quality can be poor and stress animals out – it can have too little oxygen (hypoxia), or be too hot, or not have enough sea salt. Work by the scientific community suggests that ocean acidification has far reaching consequences beyond such abiotic factors. What about the animal’s need to find food? Or reproduce? Or fight off disease? The researchers in this study wanted to take a closer look at what happens when stressors are combined. Rather than see what happens to these animals when we dial up the acid, let’s see what happens if we dial up the acid AND give them some parasites to fight off.

Methods

The researchers here used a common marine snail, the southern creeper horn snail (Zeacumantus subcarinatus) and three of their common trematode parasites. Trematodes are some nasty parasites for the horn snail: when they get into an infected snail, they replace the reproductive tissue in males with their own tissue (Figure 1), leaving them unable to reproduce.

Figure 1 – Trematode parasites in an unshelled California horn snail.  The normal horn snail (top) has orange tissue that produces sperm.  The infected horn snail (bottom) has none of that orange tissue and is instead used as a resource for the trematode parasite.  Source: https://www.sciencenews.org/sites/default/files/8417

Figure 1 – Trematode parasites in an unshelled California horn snail. The normal horn snail (top) has orange tissue that produces sperm. The infected horn snail (bottom) has none of that orange tissue and is instead used as a resource for the trematode parasite. Source: https://www.sciencenews.org/sites/default/files/8417

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

First, the snails were divided into three groups: a normal pH (8.1) group that served as the control, a low pH (7.6), and very low pH (7.4). Within those three groups, the snails were divided further into four groups: uninfected snails, and three different groups of snail infected with one of the trematode parasites.

Snails were held in tanks for 90 days and survival was assessed weekly by poking the snails with a stick and seeing if they moved. If they didn’t move two weeks in a row, they were classified as dead. Science!

Results and Significance

I’m sure you’re all thinking (as did the researchers) that the infected snails in the lower pH treatments would be more likely to die than the uninfected snails.

Figure 2:  Mortality curves for the four groups of snails, with a) being the uninfected snails, and the remaining panels being snails infected with (b) M. novazealandensis, (c) Philophtahlmus sp, or (d) Aconthoparyphium sp.  Source: MacLeod & Poulin 2016.

Figure 2: Mortality curves for the four groups of snails, with a) being the uninfected snails, and the remaining panels being snails infected with (b) M. novazealandensis, (c) Philophtahlmus sp, or (d) Aconthoparyphium sp. Source: MacLeod & Poulin 2016.

 

 

 

 

 

 

 

 

 

 

 

 

 

Surprise! The snails with the infections were resistant to the effects of low pH on survival (Figure 2). The uninfected snails showed a significant response to the decreased pH – as the pH decreased, more snails died, which was to be expected. However, when you look at the infected snails, the influence of the pH treatment was hardly present – the snails died at similar rates despite the differences in pH.

The researchers think that the indifference to the pH treatments has something to do with reproductive tissue that’s being replaced by the trematode parasite. Because the snails are effectively castrated by the parasite, they invested less energy into reproduction. This “left over” energy in their budget can now be used for the increased energy costs of dealing with the lowered pH.

Of course, this isn’t good news for the horn snail populations. Even though they may survive in low pH, these males can’t reproduce because of the parasite, meaning the population is still at risk for decline. But, this study shows us the importance of considering all the different factors at work here when we study the response of any animal to climate change. Much like no man is an island, no one factor will tell you the whole story. More multi-stressor experiments like this will give us a better idea of what to expect from future ocean conditions!

Your turn: What parallels can we draw here to marine conservation? For example, if we set up a marine protected area to protect a certain species from fishing pressure, larger predators may notice and use that “protected area” for a feeding ground. What ideas can we come up with to test and see if that’s the case?

Post your thoughts in the comments section below!

Discussion

No comments yet.

Post a Comment

Instagram

  • by oceanbites 2 months ago
    Happy Earth Day! Take some time today to do something for the planet and appreciate the ocean, which covers 71% of the Earth’s surface.  #EarthDay   #OceanAppreciation   #Oceanbites   #CoastalVibes   #CoastalRI 
  • by oceanbites 3 months 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 4 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 5 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 5 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 5 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 5 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 6 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 6 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 7 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 7 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 7 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 7 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 8 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 8 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 9 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 9 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 10 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 11 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 11 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 
WP2Social Auto Publish Powered By : XYZScripts.com