you're reading...


Marine invertebrates- no backbone just makes them easier to eat.

The Paper: Tyler D. Eddy, Marta Coll, Elizabeth A. Fulton, and Heike K. Lotze. Trade-offs between invertebrate fisheries catches and ecosystem impacts in coastal New Zealand ICES J. Mar. Sci. (May/June 2015) 72 (5): 1380-138. doi: 10.1093/icesjms/fsv009.


Delicious lobster dinner. Credit: Benson Kua.




Invertebrate fisheries in New Zealand. (a) Number of invertebrate species or groups commercially harvested in New Zealand (Ministry for Primary Industries, 2014). Only invertebrate groups that are included in the Quota Management System are shown. (b) Reported landings of invertebrate groups commercially harvested in New Zealand (FAO, 2014).

The marine invertebrate seafood industry has been expanding- meaning more people happily dine on more species of crabs, lobsters, clams, scallops, squid and other spineless creatures. The well known threat of overexploitation in finfishing (typically just called fishing) is common and even expected but we have not yet heard about huge invertebrate fishery collapses.  Invertebrate fisheries remain largely unregulated risking overuse that could ultimately destroy the fishery as well as change the ecosystem as a whole through a chain reaction in the food chain.

One tool used to create effective management plans is modeling changes to certain fishery species and habitat over time.  These models can account for information such as habitat use, feeding habits and fishing pressures to create a prediction about how the population will change over time. In many places, not enough is known about the invertebrate fishery species to make accurate models.The authors chose to model New Zealand fisheries because of their available data on its invertebrate fisheries.


The researchers used a recently published model to investigate different exploitation rates of three invertebrate fisheries in New Zealand. They explored how changing the catch numbers of lobster, abalone and sea urchin affects the fishery and ecosystem.

Each simulation ran with the catch numbers of one species changing from 0% (unfished) to 100% (total depletion of stocks).  The model then predicted changes to the number of other animals in the area.  The aim of the study was to answer the three following questions:

  1. How many other types of animals at different levels in the food chain are impacted by changes in the rate of depletion of a fishery species?
  2. How do changes to the invertebrate numbers change the number of top predators?
  3. How does the biomass of different groups change?

Results and Significance

Increasing fishing of each of the three species increased the impacts on the rest of the ecosystem through changing the population numbers of other species, and lobster showed the most dramatic effects. Low depletion levels of each species created no ill effects but after >15% depletion of lobster and abalone or >10% depletion of urchin other animals were affected.


Depletion ranges from 0 (no exploitation) to 100% (local extinction) and the present level of depletion (LOD) is indicated by the vertical line. Catch is shown as a proportion of maximum sustainable yield (MSY)

The model predicts for all three species that the current catch rate causes damage to the ecosystem and brings in animals at a rate that is not sustainable. Cutting the catch in half would maintain a sustainable fishery and minimize impacts on other species. If a  smaller catch was enforced, the model predicted greater catches in the future with larger economic rewards.

Responses were different for animals that live near the ground compared to open water species. Depletion of lobsters caused larger decreases for the open water community while abalone and urchin fishing caused larger problems for the ground species. Each of these animals consume different prey species and are victim to different predators. Shifting their numbers changes the numbers of other species in unique ways.

Modeling the potential impacts of invertebrate harvest allows us to create management plans to keep the fisheries strong. This study shows that invertebrate fisheries are connected to the rest of the ecosystem and can change the populations of animals at every level of the food chain. It also shows how different invertebrate species can impact the ecosystem in different ways. Just as we have overexploited finfish stocks, invertebrate species should not be overlooked because the threat to the ecosystem is just as serious.


What is your favorite invertebrate fishery species? What other creatures may be affected by harvesting that animal?


No comments yet.

Post a Comment


  • by oceanbites 3 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 4 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 5 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 6 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 7 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 7 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 7 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 8 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 8 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 8 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 8 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 9 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 9 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 10 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 10 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 11 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 11 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 12 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 12 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 1 year 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