Ocean of the future may make shrimp small and colorful | Science News for Students

Ocean of the future may make shrimp small and colorful

Teen shows that ocean acidification may make shrimp easier for predators to see
Nov 17, 2016 — 7:00 am EST
peppermint shrimp

This peppermint shrimp (Lysmata wurdemanni) is already a cheerful orange. A teen showed that a more acidic ocean environment could intensify that color.

Andrew Bogott/Wikimedia Commons (CC BY-SA 4.0)

WASHINGTON, D.C. — Many ocean lovers, such as Olivia Lazorik, 15, know that something big is happening to the world’s oceans. As human activities produce more and more carbon dioxide, the ocean takes up more and more. And this extra CO2 is making the ocean slightly more acidic. It’s not enough to eat the skin off your bones, like in some horror movie. But it can affect the creatures that live in the ocean, sometimes in unexpected ways. Olivia showed that the ocean of the future may produce smaller, but more colorful, shrimp. Her findings won her second place in mathematics at the Broadcom MASTERS competition last week.

Olivia, now in ninth grade at St. Edward’s School in Vero Beach, Fla., was one of 30 finalists in the 2016 Broadcom MASTERS. MASTERS stands for Math, Applied Science, Technology and Engineering for Rising Stars. This yearly competition brings middle-school science fair winners together from around the country to compete in team projects. It was created by Society for Science & the Public and is sponsored by the Broadcom Foundation. (Society for Science & the Public publishes Science News for Students and this blog.)

An acid — such as lemon juice — is a substance that reacts with a base — such as lye — to form a salt. Scientists measure how acidic or basic a liquid is using the pH scale. Acids have a pH of between 0 and 7, while bases have a pH between 7 and 14. Distilled water on its own is neutral; it’s got a pH of 7. The ocean has much more than water, though — it also contains salt, minerals and other chemicals. It’s a bit basic, around a pH of 8.1

The burning of fossil fuels such as oil or coal produces carbon dioxide. When some of that CO2 dissolves into the ocean, it reacts with water and the chemical calcium carbonate to form bicarbonates. This makes the water more acidic. By the year 2100, ocean pH could be as low as 7.5.

That’s bad news for shelled animals such as clams, which rely on calcium carbonate for their shells. Shrimp also have a hard exterior (it’s the bit you peel off before you eat them). It’s called an exoskeleton. But shrimp, it turns out, aren’t like clams. Shrimp respond to a lower pH by sucking up more calcium for their exoskeletons. So a lower pH, Olivia explains, may produce shrimp with more calcified exoskeletons.

What might that mean for shrimp inside? To find out, Olivia took home 12 aquarium tanks from the Vero Beach Marine Laboratory at the Florida Institute of Technology. The teen placed the tanks on her home’s porch and divided them into two groups. The first six tanks got three peppermint shrimp (Lysmata wurdemanni) each and were filled with water at a pH of 8.1. The second six tanks got another three shrimp each and were filled with water at the pH of the future — 7.5.

Olivia Lazorik
Olivia Lazorik (right) wades in as part of a team marine science project at the 2016 Broadcom MASTERS.
L. Doane/SSP

Before slipping the shrimp into the tanks, Olivia weighed them and took pictures. She analyzed the pictures with a computer program to determine the length of each shrimp and the intensity of its coloring. She added the same amount of food to each tank every day for 24 days and then weighed and measured the shrimp again.

After 24 days in water with a pH of 7.5, the peppermint shrimp weighed less than the shrimp in the control condition, water with a pH of 8.1, Olivia found. But while the shrimp were lighter in weight, they were also more intensely colored.

“I conclude that in the future environment the shrimp [may be] adversely affected as they do not grow as much,” she says. Olivia is also worried about the change in color, since that may affect how predators see the shrimp.

Olivia is not alone in her findings. One of the most important aspects of science is replication — when several scientists perform similar experiments and find similar results. Jennifer Taylor of the Scripps Institute of Oceanography in La Jolla, Calif., and colleagues found that another type of shrimp, when exposed to a pH of 7.5 for 21 days, also ended up more colorful than their controls. These scientists published their findings last year in the journal Scientific Reports. These more intensely colored shrimp, they noted, may not be able to hide as well from predators — making them more likely to end up as someone’s dinner.

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Power Words

(more about Power Words)

acidic     An adjective for materials that contain acid. These materials often are capable of eating away at some minerals such as carbonate, or preventing their formation in the first place.

base     (in chemistry) A chemical that produces hydroxide ions (OH - ) in a solution. Basic solutions are also referred to as alkaline. 

blog     Short for web log, these Internet posts can take the form of news reports, topical discussions, opinionated rants, diaries or photo galleries.

Broadcom MASTERS     Created and run by the Society for Science & the Public, Broadcom MASTERS (Math, Applied Science, Technology and Engineering Rising Stars) is the premier middle school science and engineering fair competition. Broadcom MASTERS International gives select middle school students from around the world a unique opportunity to attend the Intel International Science & Engineering Fair.

calcium     A chemical element which is common in minerals of the Earth’s crust and in sea salt. It is also found in bone mineral and teeth, and can play a role in the movement of certain substances into and out of cells.

calcium carbonate     The main chemical compound in limestone, a rock made from the tiny shells of ancient marine organisms. Its formula is CaCO3 (meaning it contains one calcium atom, one carbon atom and three oxygen atoms). It’s also the active ingredient in some antacid medicines (ones used to neutralize stomach acids).

carbon     The chemical element having the atomic number 6. It is the physical basis of all life on Earth. Carbon exists freely as graphite and diamond. It is an important part of coal, limestone and petroleum, and is capable of self-bonding, chemically, to form an enormous number of chemically, biologically and commercially important molecules.

carbonate     A group of minerals, including those that make up limestone, which contains carbon and oxygen.

carbon dioxide     (or CO2) A colorless, odorless gas produced by all animals when the oxygen they inhale reacts with the carbon-rich foods that they’ve eaten. Carbon dioxide also is released when organic matter (including fossil fuels like oil or gas) is burned. Carbon dioxide acts as a greenhouse gas, trapping heat in Earth’s atmosphere. Plants convert carbon dioxide into oxygen during photosynthesis, the process they use to make their own food.

chemical     A substance formed from two or more atoms that unite (become bonded together) in a fixed proportion and structure. For example, water is a chemical made of two hydrogen atoms bonded to one oxygen atom. Its chemical symbol is H2O. Chemical can also be an adjective that describes properties of materials that are the result of various reactions between different compounds.

computer program     A set of instructions that a computer uses to perform some analysis or computation. The writing of these instructions is known as computer programming.

control     A part of an experiment where there is no change from normal conditions. The control is essential to scientific experiments. It shows that any new effect is likely due only to the part of the test that a researcher has altered. For example, if scientists were testing different types of fertilizer in a garden, they would want one section of it to remain unfertilized, as the control. Its area would show how plants in this garden grow under normal conditions. And that give scientists something against which they can compare their experimental data.

dissolve     To turn a solid into a liquid and disperse it into that starting liquid. For instance, sugar or salt crystals (solids) will dissolve into water. Now the crystals are gone and the solution is a fully dispersed mix of the liquid form of the sugar or salt in water.

engineering     The field of research that uses math and science to solve practical problems.

environment     The sum of all of the things that exist around some organism or the process and the condition those things create for that organism or process. Environment may refer to the weather and ecosystem in which some animal lives, or, perhaps, the temperature, humidity and placement of components in some electronics system or product.

exoskeleton     A hard, protective outer body covering of many animals that lack a true skeleton, such as an insect, crustacean or mollusk. The exoskeletons of insects and crustaceans are largely made of chitin.

fossil     Any preserved remains or traces of ancient life. There are many different types of fossils: The bones and other body parts of dinosaurs are called “body fossils.” Things like footprints are called “trace fossils.” Even specimens of dinosaur poop are fossils. The process of forming fossils is called fossilization.

fossil fuel     Any fuel — such as coal, petroleum (crude oil) or natural gas — that has developed in the Earth over millions of years from the decayed remains of bacteria, plants or animals.

fuel     Any material that will release energy during a controlled chemical or nuclear reaction. Fossil fuels (coal, natural gas and petroleum) are a common type that liberate their energy through chemical reactions that take place when heated (usually to the point of burning).

liquid     A material that flows freely but keeps a constant volume, like water or oil.

lye     The common name for a solution of sodium hydroxide. Lye is often mixed with vegetable oils or animal fats and other ingredients to make solid bars of soap.

marine     Having to do with the ocean world or environment.

mineral     The crystal-forming substances, such as quartz, apatite, or various carbonates, that make up rock. Most rocks contain several different minerals mish-mashed together. A mineral usually is solid and stable at room temperatures and has a specific formula, or recipe (with atoms occurring in certain proportions) and a specific crystalline structure (meaning that its atoms are organized in certain regular three-dimensional patterns). (in physiology) The same chemicals that are needed by the body to make and feed tissues to maintain health.

oceanography     (adj. oceanographic ) The branch of science that deals with the physical and biological properties and phenomena of the oceans. People who work in this field are known as oceanographers .

pH     A measure of a solution’s acidity. A pH of 7 is perfectly neutral. Acids have a pH lower than 7; the farther from 7, the stronger the acid. Alkaline solutions, called bases, have a pH higher than 7; again, the farther above 7, the stronger the base.

predator     (adjective: predatory) A creature that preys on other animals for most or all of its food.

replication     (in experimentation) Getting the same result as an earlier test or experiment — often an earlier test performed by someone else. Replication depends upon repeating every step of a test, step by step. If a repeated experiment generates the same result as in earlier trials, scientists view this as verifying that the initial result is reliable. If results differ, the initial findings may fall into doubt. Generally, a scientific finding is not fully accepted as being real or true without replication.

salt     A compound made by combining an acid with a base (in a reaction that also creates water). The ocean contains many different salts — collectively called “sea salt.” Common table salt is a made of sodium and chlorine .

Society for Science & the Public (or SSP ) A nonprofit organization created in 1921 and based in Washington, D.C. Since its founding, SSP has been not only promoting public engagement in scientific research but also the public understanding of science. It created and continues to run three renowned science competitions: The Regeneron Science Talent Search (begun in 1942), the Intel International Science and Engineering Fair (initially launched in 1950) and Broadcom MASTERS (created in 2010). SSP also publishes award-winning journalism: in Science News (launched in 1922) and Science News for Students (created in 2003). Those magazines also host a series of blogs (including Eureka! Lab).

star     The basic building block from which galaxies are made. Stars develop when gravity compacts clouds of gas. When they become dense enough to sustain nuclear-fusion reactions, stars will emit light and sometimes other forms of electromagnetic radiation. The sun is our closest star.

technology     The application of scientific knowledge for practical purposes, especially in industry — or the devices, processes and systems that result from those efforts.

NGSS: 

  • MS-LS1-5
  • HS-LS2-4
  • MS-ESS3-3
  • HS-LS2-7
  • HS-ESS3-6