A threatened areaCORAL REEFS

Allen Mikey Kristen

TobySarahRyuya

SabrinaTae Wan

AsraHaris Dillon

The Great Barrier Reef: the best PPT is put on the blog.

Groups and leaders:

We will watch all three presentations. You will vote. Assessment: Individual grade for your section – slide content and presentation skills Individual grade for what you remember afterwards – worksheet.Exam question – Paper 2 Resource Booklet and Qs.

Slides must cover:

Where the Great Barrier Reef isFacts that let us know it is a biodiversity hotspot

How coral formsHow the GBR functions as an ecosystem – trophic levels, food web, energy, inputs, outputs (revision of Topic 1 and 2)

Human threats – tourism, farming, fishing, global warming

Natural threats – Predators – crown of thorns starfish, storms/cyclones/El Nino

All: Conclusion – All of these combined – equilibrium – consequences for economy/coastal defence/biodiversity.

Watch the DVD Coral Seas (The Blue Planet) 48 minutes

Look for examples of:Competition A niche A population A habitat A speciesPredation Mutualism Parasitism A community An ecosystem

Where the Great Barrier Reef isFacts that let us know it is a biodiversity hotspot

LengthNo of speciesHard coral speciesProportion soft coral out of world’s

populationNo. of world’s threatened turtlesSpecies of marine mammals

Human threats – tourism, farming, fishing, global warming

TourismOver fishingSea floor trawlingCommercial/subsistence farmingSea pollution – causesSedimentationMangrovesCoral bleaching

Natural threats – Predators – crown of thorns starfish, storms/cyclones/El Nino

DiseasesPredatorsCrown of thorns starfishStorms CyclonesEl Nino

Model answer: "Coasts"

This programme examines the world's coastal environments, "the most dynamic of all ocean habitats". The perils of living in such places are highlighted by Marine Iguanas on the Galápagos Islands, whose diet of seaweed is quickly grabbed between crashing breakers. Many shores provide sites in which to breed or lay eggs. Apart from birds, turtles are among other major species to do so, and the mass emergence of flatbacks on Crab Island in Australia is reduced by predatory herons, pelicans and other hunters. Each year, four million seabirds, comprising fourteen species, return to the island of Talan in eastern Russia to nest. By ensuring that all their chicks eventually leave at the same time, they lessen the impact of predators. The rough seas of the Southern Ocean play host to penguins, and a group of them is shown being pursued by an aggressive bull sea lion. The planet's coldest seas are in Antarctica, and on South Georgia each spring, thousands of Southern elephant seals arrive to breed. A pair of males is shown fighting a bloody battle to control a harem of females. In Patagonia, the social nature of sea lions is shown as they establish colonies, each of them several hundred strong. While in some respects it is an ideal location for the growing young, high tide brings danger for the colony as a pod of orcas habitually goes on the attack. Having snatched a victim, the predator returns to the open ocean to 'play' with it.

Real summary: "Coral Seas“

Coral reefs are so crowded that they play host to a perpetual battle for space, even among the coral itself. It starts life as a larva that becomes a polyp. Having multiplied, it hardens into a limestone skeleton and grows to form a reef. As the community flourishes, animals develop relationships with one another and such a place can feature a huge variety of ocean life. Although corals feed nocturnally on plankton, sunlight is vital because even though they are animals, each contains millions of single-celled algae. This in turn is the favoured sustenance of the humphead parrotfish, whose jaws are so powerful that it erodes much of the reef into fine sand.

Algae also grows on the top of the reef and a battle for grazing rights between shoals of powder blue and convict tangs is shown, the former being initially overwhelmed by the latter's weight of numbers before regaining the upper hand. The night-time hunting of a marbled ray alerts other predators and a group of whitetip reef sharks moves in, from which few are safe. Several breeding strategies are examined, including the acrobatic habits of brown surgeonfish and the colourful courtship of the flamboyant cuttlefish.

Humpback whales are visitors to the reef and males establish their seniority by the loudness and strength of their song. Being fixed to the seabed, corals must synchronise their reproduction with lunar phases and the rising spring temperatures.