DEEP-SEA Biology: Habitats from mesopelagic to abyssal to methane seeps; animals from viperfish to rattails to tubeworms

Alvin updates Aug. '08; New photos May '14
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amphi giant
hades

DEEP-SEA BIOLOGY

Paul H. Yancey, Ph.D.
Professor of Biology, Whitman College
Walla Walla, Washington, USA

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Biological Research and Information on Deep-Sea Habitats and Adaptations
Click button for News--button--updated June 2014
New HADAL/Trench Images/Info May 2014

The international HADES Program: 2011-2015
In the News:
A biochemical depth limit for fishes?--from our lab and HADES collaborators (2014)

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CONTENTS
These pages contain pictures, links and information on deep sea habitats and animals, with details on our studies from our many deep-sea expeditions and specimens sent to me by deep-sea researchers
If you copy and use photos, please WRITE for PERMISSION first at
Some of these photos are mine, others are ones I took from the ROV Oceanic Explorer's camera monitor or the ALVIN's various cameras.

FOR A DETAILED DESCRIPTION OF LIFE'S ADAPTATIONS TO THE DEEP SEA, SEE ALSO MY PAGE AT MARINEBIO.ORG

TOPICS
Click on the Content buttons to the RIGHT-->
or use this pulldown menu
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V. The OCEANS in TROUBLE:
Environ. issues
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VI. NEWS Updated
June 2014

Other Websites; Readings; Careers
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VII. Stuff

GO TO Prof. Yancey's Home Page

GO TO Prof. Yancey's African/Australian/American Animals Site

GO TO Whitman Biology Home Page




PART Ia. LIFE and ZONES of the DEEP: General Information
Click here for OUR SPECIFIC STUDY SITES

THE OCEANS cover 70% of Earth's surface, but are so deep that they make up about 90% of the habitats for life. For an overview of the various oceans, see Shipping by Sea - A Look at Bodies of Water Around the World

DEEP LIFE and ZONES: Life in the deep sea must adapt to unique conditions of low or no light, high pressure, low energy (except at hot vents and cold hydrocarbon seeps), and near-freezing or--at hot vents--superheated temperatures.
FOR A DETAILED DESCRIPTION OF LIFE'S ADAPTATIONS TO THE DEEP SEA, SEE ALSO MY PAGE AT MARINEBIO.ORG

Amazingly, only about 5% of the deepsea has been explored. What might be left undiscovered?

One unexplained but fairly common feature of deep animals is GIGANTISM--such as oarfish, the giant squid, etc.
.anemone.sg
Gigantic anemone, amphipod
The major deep-sea habitats (see DIAGRAM, right) include the following; click on the topics, or CLICK on the DIAGRAM, or SCROLL DOWN:

1. PELAGIC ZONES

PELAGIC ZONES:
"Pelagic" refers to the swimmers and drifters above the bottom; the main subcategories are plankton--organisms at the mercy of currents--and nekton--animals that can outswim currents. Pelagic zones are divided into layers (see Figure above, right):

--EPIPELAGIC: The familiar surface waters, where most of the energy input (sunlight) occurs, and food chains begin primarily with phytoplankton ("plant drifters"; mostly microscopic algae such as diatoms). Life can be abundant, if nutrients and sunlight are plentiful. By far the most studied habitat, it goes only to a maximum of 200m deep (maximum depth of light adequate for photosynthesis). Consider that in comparison to the average ocean depth at 4000m, going down to 11,000m!
--MESO-, BATHY-, ABYSSO-, HADO-PELAGIC: Below the epipelagic in the deeper zones, food chains are energy-poor (due to lack of sunlight) and usually begin with detritus and bacteria. Since no algae can grow in these zones, life gets sparser the deeper one goes. Most animals have watery, gelatinous low-energy muscles and other tissues, and sluggish, low-metabolism lifestyles. These features were originally thought to be ways to cope with low food energy--the "low-energy" hypothesis--but the features are also found in animals near Hawaii where there is more food available than in temperate zones. The alternative"visual-interactions" hypothesis proposes that the lack of light means that animals with eyes do not need robust muscles since they only need to be able to dart briefly in the darkness when a predator or prey come close enough to see.
These deep zones together form the largest habitat on earth and the least explored. The depths include:

  • The Mesopelagic (=midwater or "twilight zone"), where there is still faint light but not enough for photosynthesis (about 200m-1000m). Bacteria, salps, shrimp, jellys, swimming (cirrate) octopods, vampire and other squids, and fish are typical; many are bioluminescent.
  • The Bathypelagic and Abyssopelagic ("midnight zones"), which are even deeper (with depths not clearly defined). Finally, the deepest tectonic trench is about 11,000m, with those habitats sometimes called Hadopelagic. Examples of deep pelagic animals are shrimp and anglerfish, though no fish has ever been seen or caught below 8,400m. We are just beginning to study these deepest habitats; the MESOPELAGIC/Midwater page (link below) has some bathypelagic species and links.
OUR STUDIES: See our
EPIPELAGIC page

for surface animals we encounter while doing deepsea work
OUR STUDIES: See our
MESOPELAGIC/MIDWATER page

for more information and large pictures

2. BENTHIC ZONES

Bathyal seafloor scenes, 510-600m

seafloor2
Bathyal seafloor scenes, 510m

rattail
spider
Rattail fish;
Giant sea spider

BENTHIC ZONES:
"Benthic" refers to life on or in the ocean bottom; animals swimming just above are "benthopelagic."
-- The shallow zones are the Intertidal (between high and low tide levels) and the Subtidal (on continental shelves).

DEEP BENTHIC ZONES--Bathyal, Abyssal, Hadal:
--Bathyal zone: The continental slopes, usually in the range of 300-2000m.
--Abyssal zone: The general ocean bottom or abyssal plain (2000-6000m; average 4000m deep, and covering perhaps half of the entire planet);
--Hadal zone: The deep troughs and trenches ( 6000m to 11,000m max in the Mariana Trench; worldwide there are about 15 subduction trenches with hadal depths, and several deep non-subduction troughs). These have been little explored, bur are receiving renewed attention with our HADES and other programs, e.g., new camera/trap landers have recently been deployed by University of Aberdeen, Scripps Inst. Oceanogr., and James Cameron's DEEPSEA CHALLENGE sub reached the Mariana Trench bottom in 2012. All the programs have yielded news-making results (new fish species, supergiant amphipods...see NEWS page and search for "trench".)

The surface of most deep areas is mud and organic-mud mixture called ooze, though some bathyal slopes are rocky. Most life here must also cope with low food supply, and again most food chains start with detritus and bacteria. The most common abyssal fishes are the rattails or grenadiers; in the hadal zone, snailfish and cusk-eels dominate. The most common non-microscopic invertebrates are echinoderms such as sea cucumbers, brittle stars, and amphipods; but there are many other animals such as sea anemones, sponges, molluscs, crabs, seaspiders (pycnogonids), burrowing worms of many types; etc. Echinoderms such as sea cucumbers have been seen at almost 11,000m depths!
SEAMOUNTS:
Rising from the seafloor all over the world's oceans, seamounts are hills and mountains that do not reach the ocean surface. There are thought to be over 30,000 of these, most of which are unexplored. Recently several expeditions have studied some of these, and are finding a large number of new species of animals. See Seamounts Online for information.

In some places on the abyssal plain are dense fields of manganese nodules (right)--rocklike formations made of growing rings of metal oxides, made by uncertain processes. Perhaps microbes are involved, for the deep mud has many bacteria/archaea including iron-oxidizing ones that normally use natural iron for energy. Microbes like these are currently consuming the wreck of the TITANIC, which lies at about 4000m.


Manganese nodule

OUR STUDIES:
Go to our ANIMAL PAGES
for bathyal and abyssal animals
and HADAL page for trench animals

SEAMOUNTS: See pictures from SEAMOUNTS at Seamounts Online

For HADAL zone pictures, JAMSTEC in Japan has a few

3. VENTS and SEEPS

tubeworm
Seep tubeworm



Seep bacterial mats

Special Habitats--VENTS and SEEPS
These are exceptions to the rule that the deep sea is energy-poor. These unusual habitats are:

  • Hydrothermal vents (deep volcanic hot springs), mainly along the midocean ridges (but sometimes shallow, e.g., near Iceland). Here hot (up to 400C) mineral-laden water provides abundant energy; and
  • Cold hydrocarbon seeps, mostly along continental margins, where gases (methane--sometimes as methane-hydrate ice--and hydrogen sulfide) and oil seep out of the sediments and also provide abundant energy. By some estimates, there is more energy locked up in these methane ices than in all (other) fossil/hydrocarbon fuels combined.
--In both cases, microbes use these energy sources and are the base of the food chain; they often live symbiotically with animals, especially large gutless tubeworms and clams. Tubeworms at seeps in the Gulf of Mexico may be the oldest living animals in the sea (over 200 yrs old; see Nature Feb. 3 2000 issue, p.499). See the COLD-SEEP TUBEWORM, to the left. Tubeworms at vents may be the fastest growing animals in the world. Animals at seeps and vents can grow in great abundance since energy is not in short supply.
--The vent microbes use geothermally-produced energy (usually as hydrogen sulfide), in a process called chemosynthesis (see link to ONR site for more information). It has been claimed that these are the only ecosystems totally independent of sunlight. However, they probably do use some molecules such as oxygen originally from the sunlit zones. Vents are also being studied as possible sites where life first began on Earth, and perhaps where life might originate on other planets and moons such as Europa.
Additional Information at OTHER SITES:
ONR Hydrothermal Vents site;
Monterey Bay Aquar. Res. Inst. Cold-Seep site;
Penn State's Cold Seep site


Part II. Deep-Sea ANIMALS! (and Microbes):
from our study sites above
II.
ANIMALS:
use buttons to the right


mystery
MICROBES; UNKNOWNS;
WORMS; TUNICATES

New 2009
anemone
CNIDARIA
(and Porifera)

New 2009
seapig
ECHINO-
DERMS

New 2009
octopod
MOLLUSCS,
CRUSTACEA,
PYCNOGONIDA

New 2014
viperfish
MIDWATER
(Mesopelagic)

New 2009
rattail
DEEP Benthic
FISHES

New 2014
dolphin
SURFACE
(Epipelagic)

New 2009
seepscene
VENTS & SEEPS

New 2008
trench1
HADAL
(Trench) ZONE

New 2014
MY ORGANISM WEB PAGES ARE ABOVE. All have been updated in Aug. 2008 with ALVIN photos from Juan de Fuca hydrothermal vents
and in Oct. 2009 with trawled specimens from Monterey Bay.
BELOW ARE SOME OTHER WEBSITES WITH ANIMAL PICTURES:
The Monterey Bay Aquarium DeepSea page also has fine pictures and descriptions of animals off central California.
Linda Kuhnz of the Monterey Bay Aquarium Research Inst. has images of many deepsea animals: burrowing (infaunal , surface (epifaunal) site 1 , surface site 2, and a midwater site.
Dr. H. Bluhm of the deep-sea DISCOL project in Germany has pictures of many deepsea animals.
The National Oceans Office of Australia has several pages of pictures and descriptions of deep-sea animals

NOTE to Researchers: We need help identifying species with a "*" on the above animal pages. If you can help with any of these below or on the linked animal pages, please send a message below, or to Whitman College at

We have some specimens, but some are deposited at the Field Museum in Chicago and loans of the material can be arranged through Janet Voight (voight@fmnh.org) or John Slapcinsky (Slapcin@fmnh.org).
Taxonomists might want to check out SCAMIT, a S. Calif. organization working to standardize marine invertebrate taxonomy.
See also the Ocean Biogeographical Information System: " ...(OBIS) is a web-based provider of global geo-referenced information on accurately identified marine species." Also, the Census of Marine Life site details this decade-long program to catalogue as many species of marine organisms as possible, with new species being discovered routinely.

I thank those who have helped with species identifications so far: Dr. Larry Lovell, Scripps Inst. Oceanography
Roger Clark
Rubi Pohl, Austria
Chris Mah, California Academy of Sciences
Dr. Janet Voight, Field Museum in Chicago
Dr. Mary Wicksten, Texas A&M University
James Orr, Nat'l Marine Fisheries Service, Seattle;
Leslie Harris, Los Angeles County Museum of Natural History
Stace Beaulieu, Scripps Inst. Oceanography
Dr. Franz Krapp, Zool. Forschungsinstitut und Museum A. Koenig, Germany
Casey Burns, Kingston WA
Erik Cordes, Moss Landing Marine Lab