Materials: DIVE IN!:
Projector Cardstock
Computer Popsicle Sticks
Presentation CD Glue
Coral Structure Blocks Stencils
Marine Puppets Scissors
Markers

Advanced Preparation:
Students should have a basic knowledge and understanding of photosynthesis and a food web. Students will be divided into groups of four for the Maui Ocean Center visit.

Procedure:
Island Marine Ecology: PowerPoint Presentation (45 min.)
Students will watch a PowerPoint presentation that outlines coral reef ecology. This will also include the Intercalical Tissue: Signals and Signs activity.
Intercalical Tissue: Signals and Signs (15 min.)
Students will simulate communication through intercalical tissue in response to stress signals. Using their bodies to represent polyps, students will gain understanding of the coral polyp functions.

DIVE IN!
For higher level students spend more time on the Ecosystem Web slide and give more of the in depth information to explain each point. Possible methods include asking the students for examples of abiotic factors instead of explaining them. For lower level students use the pictures of the PowerPoint slide and associate the visual with real life examples. For ESOL learners reference animals and places in Hawaiian.
Teachers may keep the CD-ROM following the presentation. In class activities may include designing their own replica of an Ecosystem web, using illustrations and/or cutouts from magazines, etc.

MOC: Spatial Spectacle (30 min.)
Students will work as teams to find examples of animals occupying specific spaces of the coral reef ecosystem.

Discovery Lab: Coral Construction (30 min.)
Using materials at the OSDC, students will build a mock reef to represent the spatial distribution. Puppets or DIVE IN! activity will be added the finished structure while students observe adaptations: shape v. space.

DIVE IN!
Students can construct models of the organisms they found using poster board and tracing provided stencils. After they have finished cutting, coloring and labeling the animal and its space, tape popsicle sticks to the backs of the animals. Ask chaperones to mold themselves into a reef. Lying on one’s back and extending arms and legs makes for a decent cauliflower coral! Students will then take their animals and fit them into the proper space: in, on, above or under the reef.

Instructor Assessment:
1. What is Ecology?
2. What is an Ecosystem?
3. Is coral an animal, plant or mineral?
4. Name an abiotic factor that may be present in an ecosystem.
5. Name two out of the four spaces on the reef and an animal that lives in those spaces.
6. Why would an octopus need to fit into small spaces?
7. What do we call changes over long periods of time that help organisms adapt to their environment?

Background Information:
Ecology is the study of an organism in relation to its surroundings. Surroundings can include anything from the shape of a space to the climate of that space. Components such as climate, habitat, diet that may alter an organism’s surroundings intertwine to create an ecosystem. An ecosystem is defined as all the living factors in a given environment with its associated abiotic factors.

Abiotic factors as parts of the ecosystem are as follows:

Predation: This interaction can best be described by using a predator – prey model taken from a food web. For example ulua or jacks feeding on smaller opelu (baitfish).

Competition: This occurs when two or more organisms are competing for the same resource, be it space, food or a mate. Organisms can be of different species, of like species, or maybe even of the same offspring. These organisms may compete periodically or be in constant competition with one another.

Climate: The environment itself may hinder or aid an organism. Some plants thrive in a hot desert climate, while the same climate may not be suitable for tropical plants dependent on large amounts of rain.

Symbiosis is another group of abiotic factors that may effect an ecosystem. The interrelations organisms have can be simplified using a +/ - or O system where (+) = a benefit, (-) = a loss, and (0) = negligible impact on an organism. Examples of symbiosis:

Commensalism: (+/0) A relationship in which one organism will benefit at no expense to the host. For example, barnacles and whales – the barnacles, a usually sessile animal, on the back of a humpback whale will be moved through the water thus greatly expanding their feeding range. At the same time, barnacles cause no harm to the humpback whales.

Mutalism: (+/+) Associated organisms working together for a mutual benefit. For example zooxanthellae are stored in the coral polyps tissues. In this relationship, the zooxanthellae consume the coral's waste while providing necessary nutrients for the coral polyp.

Parasitism: (+/-) A parasite takes nutrients from the host at the expense of the host. Take for example uku (head lice). Uku feed off human blood and burrow in the scalp. Humans get nothing positive from this, only an itchy, infested head, whereas the uku are living fat and happy.

Organisms fall into a variety of different feeding guilds. The main energy source in most ecosystems is the sun (with the exception of those crazy deep-sea hydrothermal vents). Autotrophs create their own food. This is done through photosynthesis. Herbivores are the vegetarians of the animal world consuming only plants or limu (algae). Carnivores (think T-rex) are the meat eaters. Omnivores, like humans, eat both plant and animal matter. Some carnivores are also scavengers, who feed on dead animal matter usually killed by disease or by another animal. Finally at the bottom of the barrel, literally, are the decomposers or detritivores. The decomposers are composed of the dung beetles, the sea cucumbers, and all of those other organisms that eat detritus. Feeding guilds can be further specialized depending on the ecosystem. Take for example planktivores or scale eaters that are specific underwater ecosystems.

These feeding guilds fit into a model of trophic levels. The number of spaces from the main energy source to the consumer defines a trophic level. Therefore an herbivore would be the secondary level consuming plants from the primary level; while a carnivore would be at the tertiary level consuming animals from the secondary level that have already consumed plants from the primary level.

The coral reef is generally viewed as a non-vital part of the ocean environment. Coral reefs are in fact a rarity, covering less than 1% of the ocean floor. Though rare coral reefs provide an extremely unique ecosystem serving many functions for life in around the reef. Coral reefs are often dubbed the "rainforests" of the sea, because of their extreme diversity and ecological role. Like the true rainforest, coral reefs deserve conservation efforts to protect them from human impact. They provide food and shelter for the fish we eat, they protect our islands from erosion and wave damage. Medical technology is being derived from the coral reefs. For example the Mycrosporin like amino acids (MAA) found in coral have a SPF 50! Coral’s exoskeleton has the same density, calcium and vascularity as human bone and is being used for bone transplants. Currently reefs face many threats from pollution, climate and even tourism. Golf course runoff is a large pollutant here in Hawaii as are the tourists who damage the reef snorkeling. Education of the public is important to protect this valuable resource.

To define coral is rather difficult because of its complexity. It is an animal with mineral and plant components. Coral polyps are scientifically classified as an animal. Most reefs are created by colonial polyps building a reef structure commonly associated with coral. The mineral part of the coral is the secreted exoskeleton composed of Calcium carbonate (CaCo3). The chamber formed from the exoskeleton is termed a calyx. The coral reef grows by closing off a calyx chamber and then beginning the secretion of another in an upward and/or outward growth pattern.

Most corals are dependent on microscopic symbiotic alga called zooxanthellae. The zooxanthellae are the plant part of the coral, responsible for the color of the corals. Coral belongs to the phyla cnidaria, which includes the sea jellies, and like most sea jellies, coral polyps are clear. Zooxanthellae are acquired through filter feeding then stored in the polyp’s tissues. There are many different species of zooxanthellae and from time to time coral colonies may change their species of hosted zooxanthellae. The loss or release of zooxanthellae is sometimes referred to as "Coral Bleaching." When the zooxanthellae are lost, the polyps appear white, with only the calcium carbonate exoskeleton reflecting light and color. Coral bleaching usually occurs when the reef is under stress. Sources of stress include sedimentation, pollution, or climatic change such as temperature and salinity. It is possible for the reef to regain zooxanthellae and possibly find a species better suited to the adverse conditions, however the bleaching may start a chain reaction with the entire colony releasing all of their zooxanthellae. When this happens the colony will most likely parish due to lack of nutrients.

Corals are colonial animals with the exceptions of a few species (i.e. mushroom and razor coral). A colony will share nutrients and information through the connections of intercalical tissue. This tissue provides a connection among the polyps for sharing signals and nutrients. When one polyp pulls its tentacles in the signal will pass through the intercalical tissues sending alerting throughout the entire colony. Likewise if all tentacles are retracted and an opportunity for feeding presents itself signals will pass through the colony instructing the extension of tentacles.

The coral reef contributes food, shelter and space to the coral reef ecosystem. Fish like the Chaetodontids (butterfly fish) feed on the actual polyps. Uhu (parrotfish) and honu (green sea turtles) scrape algae off the reef. He’e (octopus) live in small puka (holes) beneath and in the reef. Crabs (papa’i) and lobster (ula) hide in caves. Fish (i’a) swim through and above the reef. Living space on the reef is an incredibly valuable entity of its own! Without space where would a planula settle, and where would a reef begin?

Ancient coral reefs began evolving over 500 million years ago. This evolution of the reef has provided corals with specific forms best suited to their environment. Corals grow in shapes to adapt to their environment. Influencing factors on a coral may include wave action, available light, salinity, pH and/or water temperature. These specific coral forms made spaces and niches for other organisms to fill. For purposes of this lesson, the coral reef will be divided into four spaces: in, on, above and under. Within each something of an eco-role is created. These roles have evolved and changed slowly over time. For example, over millions of years, a fish might find the crabs that live in coral crevices to be a diet with little competition. Now to effectively feed on such an organism the fish will evolve special traits that would make this feeding guild successful, as in the case of the lau wiliwili nukunuku ‘oi ‘oi (long-nose butterfly fish). Other organisms may evolve into an "eco-role" that is a symbiont of another such as the hinalea (cleaner wrasse), which provides healthcare, cleaning its host of parasites and dead scales. Some species, like the mano keep the populations healthy and in check by feeding on the dead and decrepit. The benthic organisms: loli (sea cucumber), snails, etc. feed on detrius and clean the bottom or remove the garbage. O‘pae (cleaner shrimp) act as dentist sometimes entering the mouths of their host, feeding on the remains of a previous meal! Some animals like the commensal crab of the loli just scavenge like bums, and others like pilot fish hold on for a free ride. The pa’e (crown of thorns) and petroglyph shrimp are demolition crews at work on the reef, burrowing through and feeding on the coral reef. Some fish are rather lazy, like the pili ko’a (hawkfish) and ambush their prey. A he’e (octopus) is stealth like a sleuth changing colors to blend in with the surroundings.

Coral reefs are a unique example of an ecosystem from an underwater perspective. They are entirely complex, but can be simplified to suit almost any age group. Interactions among the biotic and abiotic factors can be explained using direct examples from our island environment.

Key Vocabulary:
Abiotic – Absence of life; non-biological
Autotroph – Refers to organisms that make their own organic materials from inorganic compounds (i.e. through photosynthesis).
Biotic – Factors pertaining to life.
Calyx – The chamber-like exoskeleton secreted by a coral polyp.
Carnivore – An animal that feeds exclusively on other animal tissue.
Commensalism – A symbiotic relationship whereby one individual benefits at no expense or damage to the host.
Competition – Used to describe when two or more organisms are vying for the same resource.
Decomposers/ Detritivores – An animal that feeds on detritus.
Detritus – Dead organic or inorganic material
Ecology – The study of an organism in relation to its surroundings.
Ecosystem – All the living things in a given environment with its associated abiotic factors.
Herbivore – An animal that eats plants as its main source of energy.
Intercalical Tissue – Tissue that connects coral polyps within the colony.
Mutualism – A symbiotic relationship in which both partners benefit in some way or another.
Omnivores – An animal that feeds on both plant and animal tissues.
Parasitism – A relationship whereby an organisms takes its nutrients from the tissues of another living organism at the host’s expense.
Planktivores – An animal that feeds solely on planktonic matter.
Planula – Free floating coral larval (prior to settling)
Polyp – The body form of a sessile coral.
Predator – An animal which kills and feeds on other animals.
Sessile – Attached to the substrate
Symbiosis – A linked association between two different organisms related to variations in the physical environment.
Zooxanthellae – Photosynthetic microorganisms (usually dinoflagellates) that live symbiotically in the tissues of some coral and molluscs.

Resources/References:
Burchet, Dando and Waller. 1996. Sea Life. Smithsonian Institution Press, Washington, D.C.
Guilko, David. 1999. Hawaiian Coral Reef Ecology. Mutual Publishing, Honolulu, HI.