LEXICON | Tara, a schooner for the planet

LEXICON

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Abeam:  on a line at right angles to a ship’s length.

Anemometer: an instrument for measuring the speed of the wind or of any flow of gas.

Anticyclone: a weather system with high barometric pressure at its centre, around which air slowly circulates in a clockwise (northern hemisphere) or counter (southern hemisphere) direction. Anticyclones are associated with calm, fine weather.

Bacteria: a large group of unicellular microorganisms which have cell walls but lack organelles and an organized   nucleus. Some bacteria are beneficial, others may cause disease.  Cyanobacteria are capable of photosynthesis.

Beagle: Ship on which Darwin made a 5-year voyage around the world, collected samples and conceived the theory of evolution.

Bear away, bear off: change course away from the wind.

Benthic: an adjective from the Greek benthos, meaning ”depths of the sea.” It identifies  flora and fauna found near the bottom, or in the bottom sediments, of a sea or lake.

Biodiversity: the variety of plant and animal life in the world or in a particular habitat. Aa high level of biodiversity whichis usually considered to be important and desirable.

Bioinformatics: the science of collecting and analysing complex biological data such as genetic codes.

Biology: the study of living organisms, divided into many specialized fields that cover their morphology, physiology, anatomy, behaviour, origin, and distribution.

Biomass: the total quantity or weight of organisms in a given area or volume.

Bleaching: When corals are stressed by changes in conditions such as temperature, light, or nutrients, they expel the symbiotic algae living in their tissues, causing them to turn completely white. Corals can survive a bleaching event, but they become extremely vulnerable and may eventually die.

Bloom: a proliferation of planktonic microorganisms concentrated in one area.

Bongo net: A double net used to collect plankton, available in various mesh sizes for  selective sampling. (The name “Bongo” comes from its resemblance to bongo drums.) Bongo nets can be towed behind a boat, or lowered vertically to certain depths. The mini-Bongo can be deployed with a winch from small boats.

Bow: the front end of a boat.

Chlorophyll: pigment present in all green plants and in cyanobacteria, responsible for the absorption of light to provide energy for photosynthesis.

Ciguatera: poisoning by neurotoxins as a result of eating the flesh of tropical marine fish that have fed on toxic dinoflagellates.

Circumnavigation: sailing around the continents or the globe.

Close-hauled, beating, on the wind: with the sails hauled aft to keep the boat close to the wind.

Coccolithophores: microscopic unicellular organisms that use sunlight and calcium to build calcium carbonate shells. When they die, these shells descend to the sea bottom and form sediments.

Copepod: a small or microscopic aquatic crustacean of the large class Copepoda. Adults of the smallest species are 0,2mm, while those from the biggest species can reach 10mm.

Coral reefs: a ridge of jagged coral just above or below the surface of the sea. (See coral).

Corals: a hard stony substance secreted by certain marine coelenterates as an external skeleton, typically forming large reefs in warm seas.

Coriolis force: an effect whereby a mass moving in a rotating system experiences a force (the Coriolis force) acting perpendicular to the direction of motion and to the axis of rotation. On the earth, the effect tends to deflect moving objects to the right in the northern hemisphere and to the left in the southern hemisphere. It is important in the formation of cyclonic weather systems.

CTD (conductivity-temperature-depth): the CTD (conductivity-temperature-depth) is an instrument that generates continuous signals as it is lowered into the ocean; temperature is determined by means of a platinum resistance thermometer, salinity by conductivity, and depth by pressure. These signals are transmitted to the surface through a cable and recorded.

Ctenophore: an aquatic invertebrate of the phylum Ctenophora, which comprises the comb jellies.

Cytometry: a technical specialty concerned with the counting of cells and especially blood cells.

Darwin: 19th century English naturalist who conceived the theory of evolution and published “On the origin of species by natural selection” 150 years ago.

DCM (Deep Chlorophyll Maximum): a subsurface maximum in the concentration of chlorophyll.

Deck fitting: all the equipment found on a boat’s deck.

Depression: a region of low atmospheric pressure, especially a cyclonic weather system.

Diatom: single-celled algae with silicate walls. Many kinds are planktonic, and extensive fossil deposits have been found.

Dinoflagellate: a single-celled organism with two flagella, occurring in large numbers in marine plankton and also found in fresh water. Some produce toxins that can accumulate in shellfish and cause poisoning if eaten.

DNA: deoxyribonucleic acid, a self-replicating material present in nearly all living organisms. DNA is the main constituent of chromosomes, carrier of the genetic information.

Ebb tide or falling tide: movement of the tide out to sea, when the water moves away from the land.

Ecology: study of interaction between communities of organisms and their environment.

Environment: the surroundings or conditions in which a person, animal, or plant lives or operates, but also the natural world, as a whole or in a particular geographical area, especially as affected by human activity.

Evolution: origins and changes over time of species and populations.

Fjord: a long, narrow, deep inlet of the sea between high cliffs, as in Norway, typically formed by submergence of a glaciated valley.

Fleet: a satellite communication system using a dish that allows the connection to Internet from a boat, and the sending of  heavy video files.

Flow cytometer: instrument used aboard Tara for counting & identifying small plankton.

Foresail mast: the principal sail on a foremast.

Genetics: the study of heredity and the variation of inherited characteristics.

Genomics: science dealing with genes of species and populations.

Geochemistry: the study of the chemical composition of the Earth and its rocks and minerals.

Girus: giant virus (contraction of giant and virus).

Glider:  a type of autonomous underwater vehicle (AUV) that uses small changes in buoyancy in conjunction with wings to convert vertical motion to horizontal, thereby propelling itself forward with very low power consumption. While not as fast as conventional AUVs, gliders using buoyancy-based propulsion represent a significant increase in range and duration compared to vehicles propelled by electric motor-driven propellers, extending ocean sampling missions from hours to weeks or months, and to thousands of kilometres in range. Gliders follow an up-and-down, sawtooth-like profile through the water, providing data on temporal and spatial scales unavailable to previous AUVs, and much more costly to sample using traditional shipboard techniques.

GMT (Greenwich Meridian Time): the mean solar time at the Greenwich meridian, adopted as the standard time in a zone that includes the British Isles.

GPS (Global Positioning System): an accurate worldwide navigational and surveying facility based on the reception of signals from an array of orbiting satellites.

Great Pacific garbage patch:  a zone in the Pacific Ocean where marine currents meet, carrying floating trash that accumulates in layers. Captain Charles Moore discovered this sea of detritus, visible from his sailboat, in 1997. Since then, other concentrations of garbage have been discovered in other regions of the world’s ocean.

Gyre: a circular pattern of currents in an ocean basin. Gyres are caused by the Coriolis force. The centre of a subtropical gyre is a high-pressure zone. Circulation around the high pressure zone is clockwise in the northern hemisphere and counter-clockwise in the southern hemisphere, due to the Coriolis effect. The high pressure in the centre is due to the westerly winds on the northern side of the gyre and easterly trade winds on its the southern side. These cause frictional surface currents towards the latitude at the centre of the gyre.

Halyard: a rope used for raising and lowering a sail, yard, or flag on a boat.

Hoist : to raise a sail by means of ropes and pulleys.

Hydrothermal vents: volcanic areas on ocean floors that emit hot fluids, gases and minerals.

Imagery: a technique, which is here dedicated to marine biology and the observation of planktonic organisms. It allows three main types of analysis: flow analysis, microscopy and macrophotography.

Jib: a triangular staysail set forward of the mast.

Knots: unit of speed equivalent to one nautical mile per hour, used especially of ships, aircraft, or winds.

Krill: small shrimp-like planktonic crustacean of the open seas, eaten by a number of larger animals, notably the baleen whales.

Lamarck: French naturalist who proposed a theory of evolution 50 years before Darwin.

Leg: a section or stage between two stopovers during an expedition.

To lift, to veer aft: change direction clockwise around the points of the compass: the wind veered a point.

Long scientific station: a series of observation and sampling procedures done over a certain amount of time, varying from 24 hours to 60 hours, at a specific spot in the ocean. During a long station, all the instruments (nets, rosette, pump, etc.) are deployed at different depths: on the surface; in the DCM layer (Deep Chlorophyll Maximum, with concentrations of photosynthetic organisms); and in the mesopelagic layer (200 to 1000 meters deep).

Marine biology: the study of ocean plants and animals and their ecological relationships. Marine organisms are classified – according to their mode of life – as nektonic, planktonic, or benthic.  All habitats related to the sea are studied, from the sea surface (interface between atmosphere and water) to the abyssal depths that go down to 10,000 meters.

Marine current: a body of water moving in a definite direction, especially through a surrounding body of water in which there is less movement.

Metagenomics: the study of the collective genomes of the members of a microbial community. This involves cloning and analysing the genomes without culturing the organisms, thereby offering the opportunity to describe the planet’s diverse microbial inhabitants, many of which cannot yet be cultured.

Microbiology: the study of the great variety of microscopic living organisms.

Microorganisms: organisms smaller than 0.1 mm, visible through microscopes.

Modelling: computational techniques used to analyse real phenomena and foresee their results by applying one or several theories with a certain degree of approximation.

Multi-net or multiple net:  ensemble of several nets held together in a steel frame. This net is used for collecting planktonic organisms of different sizes, at different depths.

Nautical mile: a unit used in measuring distances at sea, equal to 1,852 meters  (approximately 2,025 yards).

Ocean desert: so-called “ocean deserts” or “dead zones” are oxygen-starved (or “hypoxic”) areas of the ocean. They can occur naturally, or be caused by an excess of nitrogen from agricultural fertilizers, sewage effluent and/or pollution from factories, trucks and automobiles. Nitrogen acts as a nutrient that triggers an explosion of algae or plankton, which in turn deplete the water’s oxygen.

Oceanography: the branch of science that deals with the physical and biological properties and phenomena of the sea.

Oligotrophic: (especially of a lake) relatively poor in plant nutrients and containing abundant oxygen in the deeper parts. Opposed to eutrophic. A eutrophic body of water is rich in nutrients and can support a dense plant population, the decomposition of which kills animal life by depriving it of oxygen.

Oxygen Minimum Zones (OMZ): places in the world ocean where oxygen saturation in the water column is at its lowest.  These zones typically occur at depths of about 200 to 1,000 meters.

Pelagic: related to the open sea.

Photosynthesis: transformation of light energy into sugars by plants and other photosynthetic microorganisms. The process by which green plants (and certain other organisms) use sunlight to synthesize nutrients from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a by-product.

Phytoplankton: plant-like plankton that carries out photosysnthesis.

Plankton: living organisms that drift in the oceans. From the Greek word  planktos, meaning “wandering.” Plankton can be extremely small, including viruses that measure only 20 to 300 nanometers. Or they can be very big: jellyfish 2 meters in diameter, and siphonophores 50 meters long. Plankton can be plant-like, carrying out photosynthesis (phytoplankton) or animal-like, feeding on other organisms (zooplankton), or both at the same time. Some organisms are planktonic for a limited period of time in their life cycle – for example fish larvae. Plankton accounts for 98% of the oceans’ total biomass.” Phytoplankton produces 50% of the oxygen we breathe!.

Points of sail: describe a sailing boat’s course in relation to the wind direction.

Port: the left side of a ship or aircraft when facing forward. The opposite of starboard.

Port tack: a sailboat’s heading when the wind is coming from the left, or port side.

Protists: unicellular organisms with nuclei, ancestors of all plants and animals. Some, such as diatioms, are photosynthetic. They build shells and skeletons of silica, calcium, or cellulose. When they die they sink to the sea bottom, thus sequestering carbon from the atmosphere in the deep sediments.

Reef: each of the several strips across a sail which can be taken in or rolled up to reduce the area exposed to the wind.

To reef: take in one or more folds of a sail to decrease the sail’s surface: reef the mainsail in strong winds.

Rigging: the system of ropes or chains employed to support a ship’s masts (standing rigging) and to control or set the yards and sails (running rigging).

RNA: ribonucleic acid, present in all living cells. Its principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins.  In some viruses, RNA rather than DNA carries the genetic information.

Rope: a cord or line made of intertwined strands

Rosette: Oceanographic instrument equipped with multiple bottles in a round frame, used for collecting samples of water at different depths.

Running rigging: rigging used primarily in setting, furling, and otherwise handling sails and movable spars.

Secchi disc: an opaque disc, typically white, used to gauge the transparency of water by measuring the depth—known as the Secchi depth—at which the disc ceases to be visible from the surface. Created in 1865 by Italian Jesuit and astronomer, Pietro Angelo Secchi, the Secchi disc is the oldest marine instrument used aboard Tara.

Shroud: a set of ropes, part of a sailboat’s standing rigging, that support the mast or topmast.

Spinnaker: a large three-cornered sail, typically bulging when full, set forward of the mainsail of a racing yacht when running before the wind.

Starboard: the right side of a boat, when facing forward. The opposite of port.

Staysail: a triangular fore-and-aft sail extended on a stay.

Stern: the rearmost part of a boat.

Tack: act of changing course by turning a boat’s head into and through the wind, so as to have the wind on the opposite side.

To tack: change course by turning a boat’s head into and through the wind.

To gybe: change course by swinging the sail across a following wind.

Taxonomy: branch of science concerned with classification, especially of organisms; systematics. The Swiss botanist, Augustin Pyramus de Candolle originated this science of classification.

Transect: a straight line or narrow section through an object or natural feature or across the earth’s surface, along which observations are made or measurements taken.

Upwelling: an instance or amount of seawater, magma, or other liquid rising up.

Virus: an infective agent that typically consists of a nucleic acid molecule in a protein coat, too small to be seen by light microscopy, and is able to multiply only within the living cells of a host. Viruses can sometimes cause death for massive numbers of bacteria, protista or animals.

Winch: a hauling or lifting device consisting of a rope or chain winding round a horizontal rotating drum, turned typically by a crank or by motor.It is to be found on a boat’s deck.

Wind hole: absence of wind.

Wind shadow: dead air in the lee of another boat or obstruction such as a jetty.

Yankee: a large jib set forward of a staysail in light winds.

Zooplankton: animal-like planktonic organisms, and the larval and embryonic stages of most marine organisms.