MARICULTURE
Plankton, Water Movement, and The Hautean Ocean
Here at Inland Aquatics we strive to duplicate
natural ocean conditions in every conceivable way. So, we were very careful to
choose methods of moving water that would imitate wave and current action in a way that
would not destroy the planktonic life present in our system water.
You see, plankton can not easily survive the
enormous trauma (called sheer) that is produced by traditional pumping techniques.
Traditional pumps use relatively fast motors, turning at high speeds in order to achieve
desired flow rate. The differential in speed between the pumping mechanism and the water
itself causes a great deal of sheer stress which is too traumatic for most planktonic
life. That is why it is necessary for us to use the significantly larger and less energy
efficient non-traumatic pumps which move liquids with minimal sheer stress.
The Archimedes Screw Pump is one type of
non-traumatic pump. Internal fins, located within the spinning tubes before you, are
twisted in a screw-like pattern. These fins turn slowly, carrying the water gently up
through the pump housing without damaging the planktonic life within the water. This
simulates large ocean currents, mixing the water and distributing plankton throughout the
system.
A second type of non-traumatic pump used here in
the facility is a type of airlift pump, the Water Blower. Pressurized air is pumped to the
bottom of a well that contains a long pipe. Air bubbles rise up the pipe, driving water up
and into distribution boxes built high above our systems.
Regardless of which pump is used, gravity forces
the water back down through the tanks and eventually back to our filters where we simulate
wave action while we purify the water.
The
Self-Cleaning Ocean
Seventy percent of the world's surface is covered
by water. That's a lot of water to keep clean! However, Mother Nature has a
wonderful natural ability to filter the oceans, to control, store and bind toxic
concentrations, allowing aquatic creatures to thrive. Pollutants, resulting from fish and
invertebrate waste production and decaying plant and animal matter, are eliminated in a
variety of ways.
These pollutants consist mostly of nitrogen
compounds (ammonia [NH3], nitrite [NO2-],
nitrate [NO3-]) and phosphorous compounds (phosphate [PO43-]).
Animal secretions and several different types of bacteria that feed on detritus (waste)
and decaying matter produce these compounds, commonly referred to as nutrients. While some
bacteria contribute to nutrient production, others actually consume those nutrients,
converting them into various, less toxic substances.
In the wild, however, only 10 - 30% of the
available nutrients are utilized by bacterial action. The remaining 70 - 90% either settle
into deep ocean trenches or are used by algae and higher plants as food. Nutrients are
utilized during plant photosynthesis as fuel and are further broken down or stored in
plant tissues.
In reefs, where plants are supplied with abundant
sunlight, intense wave action, and strong currents, nutrient uptake occurs at a great
rate, generating more plant material than in almost any other environment. Compared with
the prolific animal life, however, few plants are apparent on most reefs. The high rate of
plant production is accomplished mostly by a small, seemingly insignificant group of
plants known collectively as algal turfs.
Algal turf is a term used to describe a short,
thick bed of living algae. These beds grow on all illuminated reef surfaces and are
present in massive amounts. Their growth rate, and therefore their capacity for nutrient
uptake, is two to three times greater than most terrestrial plants, including carefully
tended agricultural crops. Algal turfs process a great majority of the available nutrients
in reef waters and their growth is kept in check by the constant grazing of herbivores
such as tangs and urchins.
The Sun, The
Moon, and The Creatures of The Reef
Ninety-three million miles away, spinning through
the empty silence of space, there lies an entity without which life on Earth would be
nonexistent. The Sun provides the seemingly unlimited energy that sustains all beings. It
heats our planet, is the source of our weather, and to a large extent, dictates the wind,
tides, and ocean currents. Natural sunlight fuels plant photosynthesis and growth.
Herbivores gain their energy from eating the plants while carnivores, in turn, gain their
energy from eating the herbivores. This complex food web is only possible due to the Sun's
effects on the Earth.
The intensity of sunlight at the Earth's surface
has been a major factor in the evolution of life around the world. In the northern and
southern hemispheres sunlight strikes the atmosphere at such an angle that much of the
light is refracted back into space, reducing its intensity at the surface. Nearer the
equator, however, light follows a direct path down through the atmosphere and is most
intense in these regions. Therefore, plants and animals, which require strong illumination
year round, are primarily found in areas at or near the equator.
As intensity is important to light loving
organisms, so is the spectrum. The spectrum consists of all of the wavelengths of light
being emitted by the sun. For example, the visible wavelengths are those that can be seen
by the human eye. We recognize them as colors reflected from the pigment within the
molecules of all matter. The visible wavelengths lie roughly in the middle of the total
spectrum with ultraviolet light at the short-wave end and infrared light at the long-wave
end. Ultraviolet light produces sunburn and tanning of human skin while infrared light
produces the warmth that we feel when exposed to sunlight and certain other types of
lighting.
Creatures of the coral reef are dependent on the
Sun for the same reasons as their terrestrial counterparts. Aquatic plants serve a vital
function by purifying the ocean waters and providing an essential food source. But
sunlight also sustains marine life in a different and most interesting way.
Many corals and other invertebrates have a
symbiotic relationship with algae living within their tissues! This algae, called
zooxanthellae, lives within the body of its host and provides, as a byproduct of
photosynthesis, carbohydrates, lipids and amino acids. These simple organic compounds
satisfy a major portion of the invertebrate's food requirements in most cases. In other
cases the zooxanthellae provide little in terms of food production but instead maintain
internal pH levels within the coral tissue that are essential to calcium carbonate
skeletal formation.
Some fishes and many corals also have a very
interesting relationship with the moon. Sunlight that reflects off of the moon at night
travels to the Earth and in some cases (like the full moon) is quite bright. Strong
moonlight penetrates the murky darkness of the night and produces distinct behavioral
changes in aquatic creatures. Many fish species only spawn during certain phases of the
lunar cycle and some corals are known to reproduce only in the days immediately following
(preceding too ??) the full moon. These events occur at specific intervals, and the full
moon, in all its brilliance, often triggers mass spawning.
It is critically important for the spawning
activity to be orchestrated in this manner because fertilization in most of these species
is external. Therefore, the sperm and eggs must be released into the ocean currents
simultaneously in order to assure fertilization and successful reproduction. Successful
reproduction is also at the core of our efforts to duplicate. . . .
Sunlight and
Moonlight over The Hautean Ocean
The most obvious light fixtures in our facility
are the large, bell shaped, 400 watt metal halide lights. Metal halide bulbs reproduce,
most closely, the full spectrum of the sun, providing ultraviolet, visible, and infrared
wavelengths. Generally, specimens kept in reef aquariums are light loving creatures from
equatorial areas and, as powerful as these bulbs are, it is still necessary to place many
of them very close to the surface of the water in order to approach the intensity of the
Sun at the equator. Remarkably, light energy decreases by 75% when the distance from the
light source is doubled. Accordingly, if we raised the metal halide fixtures just inches,
the intensity would drop dramatically. Near the ceiling of the facility you will notice
banks of fluorescent lights. These standard fluorescent bulbs are timed to come on just
before and just after the metal halides in order to simulate the diffuse light conditions
at dawn and dusk.
You may also notice incandescent bulbs in place
over our systems. These bulbs come on at night and are controlled by a small computer.
They simulate the phases of the Moon, shining most brightly during the nights of the Full
Moon, less intensely during the Half Moon, dimmer yet during the Quarter Moon, and not at
all during the New Moon.
This attention to detail in lighting our systems
is just one more example of how our ecosystems model the ocean environment.
Ocean Motion
and Planktonic Life
The oceans and seas of our world are constantly
in motion. The wind, fluctuations in temperature and salinity, and the gravitational
affects of the sun and moon drive tides, and the resulting currents and waves. This
eternal motion churns and stirs, delivering essential trace elements and equilibrating
salinity levels. These currents also deliver plankton to awaiting filter feeders and
appropriate colonization sites throughout the underwater world, driving the ongoing
evolution of our ecosystem.
Plankton is a complex mixture composed of the
larvae of fish, corals and other invertebrates, algae, and numerous single cell organisms.
It is a universal food source for the creatures of the deep. The fish and invertebrate
larvae are part of the planktonic community and drift along with the other planktonic
constituents, eating, growing, and finally metamorphosing into larger, adult organisms.
The corals and most of the invertebrates settle to the sea floor, taking up permanent
residence there.
As adults many are still dependent upon plankton
as a major food source. But this metamorphosis is not always completed. Larger beings also
feed on the plankton and the defenseless larvae in the process. The largest fish in the
world, the Whale Shark, feeds exclusively on plankton and any small fish that may be in
the vicinity. There are also 11 species of filter feeding whales who dine on plankton and
schools of small fish. From the microscopic to the mammoth, life in the sea is highly
dependent on plankton.
Mature corals and many other invertebrates are
sessile, that is, they are fixed in place and can not move about. These filter feeders
capture the tiny planktonic particles as they pass by and are depend upon ocean currents
and tides to bring the planktonic food to them. Planktonic matter is, however, very
delicate. It can not withstand a great deal of trauma. How then does it survive this
turbulent mixing action?
The forces that move water in nature are
enormous. Currents rip through the open ocean, stretching from continent to continent.
Tides pull millions of gallons of seawater out toward the great deep and then reverse,
sending tons of water rushing back toward shore. But these powerful forces are spread out
over such a wide expanse that plankton is able to thrive even under such intense
circumstances. |
CHANGING THE WAY 
