Exercise 82 . Look through the text to find out who this text is intended for:

a) general reader; b) students of the faculty of Bioresources and Aquaculture;

c) professional veterinarians.

Exercise 83. Answer the questions and discuss the main idea of the text. Ask questions to the text.

1. What are the main environmental problems concerning marine ecosystems?

2. How do high temperatures impact to the symbiotic relationship between corals and algae?

3. What does eutrophication mean?

4. What is the reason of coral reefs destruction?

5. Where can dead zones be found?

6. What makes people develop fishing as a traditional activity?

7. What problems do people meet with by seeking to exploit the ocean for oil and gas?

 

Unit 5

Forests of the Sea

Text A

Phytoplankton & Marine plants

VOCABULARY LIST TO TEXT A

eukaryote n	[juːˈkarɪəʊt]	эукариот
seaweed n	[ˈsiːwiːd]	морская водоросль
loose adj	[luːs]	свободный
poisonous adj	[ˈpɔɪzənəs]	ядовитый, вредный
harvest v	[ˈhɑːvɪst]	собирать урожай
nourishment n	[ˈnʌrɪʃm(ə)nt]	питание
fission  n	[ˈfɪʃ(ə)n]	разделение
armor n	[ˈɑːmər]	защита
kelp  n	[kelp]	бурая водоросль
phylum  n	[ˈfaɪləm]	тип

 

Exercise 84. Read and translate the following word s and word combinations from English into Russian.

Phytoplankton, diatoms, dinoflagellates, algae, chlorophyll, cyanobacteria, free floating, substrate, seaweeds, poisonous, nanoplankton, picoplankton, silica, frustules, chains, whole, zooxanthellae, bioluminescence, filaments, branched plants, broad flat plates, ruffled plants, motile spores, subpolar regions, bottom-dwelling animals, epiphytes.

Read the text and translate. Be ready to discuss.

    The plant kingdom is made up of multicellular, photosynthetic eukaryotes. These multicellular organisms contain specialized cells that perform different tasks.

Marine algae (seaweeds and phytoplankton) are a loose group of some of the simplest organisms that contain chlorophyll (like plants) but include members of both the Empires Prokaryota (Kingdom Bacteria – e.g., cyanobacteria) and Eukaryota (Kingdoms Chromista, Plantae and Protozoa…). Marine algae though are abundant throughout the ocean and can either float freely or cling to substrate such as rocks and reefs. The majority of seaweeds are classified as red algae (~6,000 species). There are also brown algae (~2,000 species) and green algae (~8,000 species). None of the algae species are known to be poisonous, and many species are harvested for human consumption.

Phytoplankton

Phytoplankton are microalgae that form an essential component of the marine food chain. These single-celled plants provide nourishment to many marine species and they also play an important role in regulating the amount of carbon in the atmosphere. There are two main types of the larger phytoplankton species: Diatoms and Dinoflagellates. Smaller phytoplankton categorized as nanoplankton and picoplankton.

 

Diatoms

The cell walls of diatoms are made of silica formed into their characteristic “pillbox” shape. Diatoms are composed of two valves or frustules, one on top of the other, within which the living matter of the diatom is found. Diatoms are either found singly where each individual lives in a single box, or found in chains. Diatoms reproduce by dividing in half. One half is attached to the top valve, the other is attached to the bottom valve. Once the division takes place, each half creates a new valve to form another whole. The new valve is secreted in the old valve, therefore the average size of each diatom is reduced with every new generation. It is thought that there are as many as 100,000 species of diatoms currently inhabiting the earth, and they occur in both fresh and saltwater.

 

Dinoflagellates

Dinoflagellates are the other primary form of large phytoplankton with about 2,000 species. Unlike diatoms, dinoflagellates are mobile through the use of a flagella. Also unlike diatoms, they do not have an external skeleton made of silica, however they are protected by cellulose. dinoflagellate - Ceratocorys sp.Dinoflagellates are typically solitary and do not form chains like diatoms. Like the diatom they reproduce through fission. Once divided, each half retains half of the original cellulose armor and replaces the missing half to form a new whole. Some dinoflagellates can produce toxins that are released into seawater. When there are large blooms, a phenomenon known as red tide occurs. In some cases increased levels of dinoflagellate toxin may cause other marine life to die. The symbiotic algae found in many corals, or zooxanthellae, are actually a non-mobile species of dinoflagellate. Dinoflagellates have strong bioluminescence and have been a source of fascination for sailors and other mariners as their ships pass through waves which become lit up by these organisms at night.

 

Algae

Algae are photosynthetic eukaryotes that are either unicellular, colonial, or multicellular. Algae with at least some multicellular members are grouped into two main Empires or Domains (Prokaryota and Eukaryota) and then further down into multiple Kingdoms (e.g., Plantae), Supergroups, Divisions, etc. mainly in the Eukaryota Domain: Phylum Rhodophyta (red algae), Class Phaeophycea (brown algae) and Phyla Chlorophyta and Charophyta (green algae). Red and brown algae species are most commonly marine; green algae are found in abundance in both marine and fresh water.