Tag: Crustaceans

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Volcanoes Transforming Dark Depths by Douglas J. Lanzo

plate tectonics
plumes of fire, sulfur and ash
erupting undersea

by Douglas J. Lanzo

Magma erupts through ocean floors from the earth’s mantle when oceanic plates collide with, or tear away from, each other, with staggering force.  This results in spectacular undersea volcanic activity that forges massive sea mounts from plumes of magma that thrust toward the ocean’s surface with incredible heat, speed and fury.  Yellow-orange magma turns red and then further glassy black as it cools so quickly that crystals do not have time to form, spewing plumes of sulfur and billowing ash into surrounding waters. 

While this activity brings death to some sea creatures, others thrive off of it, with aptly named Pompeii worms, vent shrimp, yeti crabs and giant tube worms thriving off the bacteria and superheated minerals found in abundance by these smoking-hot hydrothermal vents.

This activity is on such a massive scale that over time it can produce entire volcanic island chains, such as the Hawaiian Islands.  Even when a sea mount does not become a “Mauna Kea” and pierce the ocean’s surface, it can rise for thousands of meters and form one of the highest mountains on earth.  Just for the record, Hawaii’s now dormant volcano, Mauna Kea is over 10,000 meters in height when measured from its base on the Pacific Ocean’s floor, which dwarfs Mount Everest’s mere 8,849-meter height.

Further reading:

To learn more about this awe-inspiring undersea tectonic activity, I highly recommend the breathtaking 2017 BBC Blue Planet II (2017) Episode 2 “The Deep” documentary narrated by Sir David Attenborough and the 2006 BBC Planet Earth Episode 11 “Ocean Deep”. 

For some good reading on it, check out the Underwater Volcanoes webpage published by the Woods Hole Oceanographic Institution under its Ocean Learning Hub at https://www.whoi.edu/ocean-learning-hub/ocean-topics/how-the-ocean-works/seafloor-below/volcanoes/.

Author bio:

Doug is an award-winning American author and poet of over 560 internationally published poems whose debut novel The Year of the Bear won the Ames Award for YA Books and whose second book I Have Lived was named American Book Fest Novella of the Year. His Author’s website is www.douglaslanzo.com.

Check out other sciku by Doug here.

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Cobwebs to Foodwebs by Dr. Jon Hare

collecting
fish stomach contents
from file cabinets

By Jon Hare

Field studies take a lot of effort. Think of studying fishes in an estuary – where a river meets the sea. You need the expertise to know the fishes and how to take the variety of biological samples including earbones, stomachs, and gonads. You need a boat and gear to catch fish of different sizes and habits. You need to be able to deal with weather, seasons, and the other elements of nature. You need a group of people with varying expertise committed to work together. You need funding for the project. And the field effort is just the beginning – samples need to be processed in the laboratory, data compiled and analyzed, the results published, and the data made available. Now think about how many field studies or parts of field studies never make it to those final steps of dissemination. What happens to these studies? What happens to all that effort? 

Hanson and Courtenay (2020) describe the fate of one such effort. A multi-year fish-related field program was undertaken from 1991 to 1993 to describe the structure and function of the Miramichi River and Estuary ecosystem in eastern Canada. After several years, the project ended owing to a change in priorities (and funding); the team of scientists and fishers went their separate ways. Some of the results were published – primarily around high profile species like Atlantic cod and Atlantic salmon. However, many of the samples and much of the data never made it to the dissemination stage of science. 

The study by Hanson and Courtenay is part of an effort to recover the large amounts of field data stored in old file cabinets, on floppy disks, and in unpublished theses. In their study, Hanson and Courtenay use data collected during the Miramichi Estuary program and present detailed descriptions of the stomach contents of more than 8,000 individual fish across a range of species. Through these analyses, they describe the seasonality in the estuary both in terms of fish occurrence and diet. They also identify a small shrimp species (Crangon septemspinosa – Seven-spined Bay Shrimp) as a keystone species, linking estuarine and coastal foodwebs. Although the findings are not earth-shattering, the results and data are now available for future studies, which could model foodweb dynamics in the ecosystem (e.g. using EcoPath) or document ecosystem changes over the past three decades (a neat example from Long Island Sound, USA). Field studies and the subsequent research based on field studies are essential to developing strategies for ecosystem resilience and climate adaptation and ultimately for living sustainably within the earth system. 

Original research: Hanson, J. M., & Courtenay, S. C. (2020). Data Recovery from Old Filing Cabinets: Seasonal Diets of the Most Common Demersal Fishes in the Miramichi River Estuary (Atlantic Canada), 1991–1993. Northeastern Naturalist, 27(3), 401-433. https://doi.org/10.1656/045.027.0302

Dr. Jon Hare is a scientist who works in Woods Hole, Massachusetts. His research background is fisheries oceanography and climate change impacts on marine fisheries. Check out Jon’s other sciku ‘Owls of the Eastern Ice’, ‘Varves’, ‘Signs of Spring’ and ‘Glacier Mice‘.

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Shrimp molting by Prof Hortense Le Ferrand

Hiding, weak and soft,
Mantis Shrimp matures and grows,
Preparing attack.

by Prof Hortense Le Ferrand

The Mantis Shrimp is an extraordinary animal in many ways. One of its striking features is its dactyl club: this is a biomaterial that is so hard and tough that it uses it to dismantle crabs and break seashells. But the Mantis Shrimp also grows by molting: during this process, it discards its club, and builds a new one.

In the paper by Amini et al (2019), the club of the Mantis was dissected during its maturation, from day zero to one month. It was observed that a thin membrane, initially folded into a cavity at the centre of the “old” club got inflated, before slowly being converted into the hard deadly appendage. The Mantis remained hidden in its nest until the biomineralization completed and the extraordinary mechanical properties of the club got recovered.

Original research: https://doi.org/10.1073/pnas.1816835116

Dr Hortense Le Ferrand is an Assistant Professor at Nanyang Technical University, Singapore. Hortense’s interests are on the fabrication and design of novel materials and systems inspired by nature. Check out her earlier sciku ‘Closing the Trap’ here.

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Consider the lobster

To know global trade,

consider the lobster from

trade route to market.

 

There has been a 515% increase in the trade of fisheries products for human consumption from 1976 to 2014. This international scale leaves small-scale fishers and fishing economies vulnerable despite an apparent global market.

By mapping the global trade routes of lobsters Stoll et al (2018) have revealed vulnerabilities of small-scale producers in North America to changes in a small number of end-markets. In particular the trade routes make it harder to identify and anticipate risk – should the demand change (as a result of a trade-war between the USA and China for instance) the impact on the $1.5 billion-a-year Maine lobster industry would be vast.

This sciku also includes a reference to David Foster Wallace’s collection of essays – Consider the Lobster.

Original research: http://dx.doi.org/10.3389/fmars.2018.00239

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The year’s best species

Mystery protist.

Apes, snailfish and amphipods.

The year’s best species.

 

Every year since 2008 the College of Environmental Science and Forestry has released a Top 10 New Species list. 2018’s selection include single celled organisms, plants and animals (including two species of beetle) as well as a prehistoric marsupial lion identified from fossils. All 10 species are fascinating but those highlighted in the sciku are:

Protist – Ancoracysta twista, a single celled predatory Eukaryote with harpoon-like organelles that it uses to immobilise its prey. Intriguingly its evolutionary origins are unclear and it doesn’t fit neatly within any known groups.

Ape – Orangutans now come in three flavours: Bornean, Sumatran and now a newly identified Southern Sumatran species of orangutans. It is the most endangered great ape in the world.

Snailfish – Whilst snailfish are found at all depths, 2018’s species is the deepest fish in the sea, found in the Mariana Trench at 7,966 meters below the surface. It appears to be the top predator in its benthic community and is tadpole-like and around 4 inches long.

Amphipod – Epimeria quasimodo is found in the Antarctic Ocean. The 2 inch long crustacean takes its name from the hunchback of Notre Dame and has beautiful vivid colours.

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Immigrant crabs

Immigrant tree crabs

Move from mangrove to salt marsh

…but it’s not the same.

 

Mangrove tree crabs have responded to climate change by moving northwards into a novel habitat: salt marsh. The crabs used to show site fidelity in their historic habitat but the faecal cues they used for this are now often washed away in the salt marsh which is regularly flooded. Climate change may therefore be indirectly affecting foraging behaviour and predation risk. Cannizzo & Griffen, 2016.

Original research: https://doi.org/10.1016/j.anbehav.2016.08.025