Tan Jiefeng (21) 2i1
Science ACE
Research in detail an animal whose survival is under threat. Using library references such as
encyclopedias, National Geographic magazine and wildlife books, determine all the factors,
biotic and abiotic, that affect the survival of your chosen animal.
Chosen animal
Common name: Dwarf seahorse
Scientific name: Hippocampus zosterae
Habitats: Seagrass beds, floating vegetation, mangrove roots, and coral reefs from Bermuda and the
Caribbean to Florida, and throughout the Gulf of Mexico
Size: Up to 5cm
Diet: Living prey, including small crustaceans such as amphipods, small shrimps, other small
invertebrates, and fish fry
Temperatures: Tropical and subtropical/warm-temperate waters
Article on the species of Hippocampus Zosterae facing extinction due to an oil spill in the Gulf of
Mexico
One of the world’s smallest seahorse species could disappear due to the Gulf of Mexico oil spill and subsequent
clean-up efforts, conservationists from the Zoological Society of London (ZSL) warned today.
NGS stock photo of dwarf seahorse by Robert Sisson
“The dwarf seahorse (Hippocampus zosterae), found only in waters off the Gulf Coast, now faces a bleak future
after its much of its habitat was destroyed by the spill,” ZSL said in a news release.
“Scientists are worried that the clean-up process could further diminish dwarf seahorse populations and other
marine life,” ZSL added.
Conservationists from the ZSL Project Seahorse team are urging BP to minimize the use of chemical dispersants
and the burning of oil during the clean-up process, which is expected to take years, ZSL said.
The conservation charity said:
“Dwarf seahorses, which are less than one inch long, produce few young, making them vulnerable to
environmental change.
“The population of dwarf seahorses is expected to decrease dramatically during the clean-up, after the spill
exposed them to high levels of oil toxins and destroyed large swaths of their food-rich habitat.
“To slow the oil spill’s movement, BP has burned off the oil caught in seagrass mats floating in open water. While
most seahorses live in seagrass beds in the coastal shallows of the Gulf, others live in these loose mats of
vegetation offshore.
“Burning these mats has killed many marine animals while depriving others of their habitat and exposing them to
further toxicity.”
NGS stock photo of dwarf seahorse by Robert Sisson
“Seagrass is vital to the long-term health of coastal ecosystems, sheltering marine animals, acting as fish
nurseries, improving water quality, and preventing erosion. In extreme cases where seahorses are at high risk of
poisoning such as this one, seagrass mats and beds can be cut to reduce toxic exposure,” said Heather
Koldewey, ZSL’s program manager for the International Marine and Freshwater Conservation Programme.
“However we are urging BP to continue to use booms in the clean-up to isolate the oil slicks. These can be
skimmed, left to evaporate, or treated with biological agents like fertilisers, which promote the growth of microorganisms that biodegrade oil,” Koldewey said.
“It’s absolutely critical that measures be taken to preserve the seagrass mats and beds during this
vulnerable time.”
Heather Masonjones, a seahorse biologist at the University of Tampa, said: “It’s absolutely critical that measures
be taken to preserve the seagrass mats and beds during this vulnerable time.
“Incidents such as the explosion of the Mariner Energy oil platform, in the Gulf of Mexico only last Thursday,
demonstrate how we must act quickly and carefully to give these fragile marine species the best chance of
survival.”
ZSL is an international scientific, conservation and educational charity. It runs two zoos, including London Zoo,
carries out scientific research at the Institute of Zoology, and is involved in field conservation internationally.
Posted by David Braun from media material submitted by ZSL.
Biotic factors

Availability of habitat
o Without a habitat, the dwarf seahorse will not have a place with suitable conditions
for survival, and a habitat plays an important part in the seahorse’s survival as it has
many purposes (e.g. camouflage  escape from predators).

Temperature of water
o The dwarf seahorse needs suitable water temperatures as it cannot survive in
temperatures which are too hot or too cold.

Level of nutrients in the water
o The dwarf seahorse is an aquatic organism and the level of nutrients directly
affects the survival of it. Also, if there are toxins in the water, the survival of
the dwarf seahorse is also affected.
Abiotic factors



Availability of food
o The dwarf seahorse needs to consume food to gain energy for life processes
like growing.
Presence of predators
o Predators consume the dwarf seahorses and decrease their population.
Human demand
o Dwarf seahorses are commonly used for aquarium trade and also for Chinese
medicine which results in the decrease in the population of the seahorses.
How has the oil spill in the Gulf of Mexico affected the species of Hippocampus Zosterae?
The dwarf seahorse produces few young at a time, thus it is very vulnerable to environmental
change. The oil spill in the Gulf of Mexico, which is the habitat of the dwarf seahorses, has caused
the species to face extinction. Firstly, the oil spill has released many oil toxins into the water.
Furthermore, chemical dispensers have been used to clear the oil, further polluting the water. The
oil is also burned in the clean-up process. In efforts to stop the oil from spreading further, oil
trapped in seagrass are burned too, and this destroys the habitat of the dwarf seahorses, and also
increases the temperatures of the waters making it unsuitable. This clean-up process is speculated
to take many years, and the numbers of dwarf seahorses are gradually dwindling. The organisms
which are food for the dwarf seahorses are also decreasing in numbers which further affects the
survivability of dwarf seahorses. These seahorses are exposed to high levels of toxicity, and are
losing their habitat and food, thus they are on the brink of extinction.
Sources:
http://newswatch.nationalgeographic.com/2010/09/07/worlds_smallest_seahorse_may_be_exterm
inated_by_oil_spill/
http://animaldiversity.ummz.umich.edu/site/accounts/information/Hippocampus_zosterae.html
http://www.sms.si.edu/irlspec/hippocampus_zosterae.htm