Lecture Review: Pelagic & Benthic Marine Environments, Fisheries, and Aquaculture

This set of vocabulary flashcards covers key concepts from the marine environments lecture, including plankton classification, oceanographic scales, fisheries management, aquaculture innovation, and reproductive strategies.

Pelagic environment

The region of the open ocean stretching from the upper surface down to the abyssal plain at $3-6\,km$ deep.

Benthic environment

The environment consisting of anything living on or in the sea floor, including soft and hard substrata.

Holoplankton

Planktonic organisms that spend their entire life cycle in the plankton (e.g., copepods).

Meroplankton

Organisms that spend only part of their life cycle in the plankton (e.g., sea urchins, crab zoea, fish larvae).

Picoplankton

Plankton in the size category of $0.2-2\,\mu m$, primarily consisting of bacteria.

Nanoplankton

Plankton in the size category of $2-20\,\mu m$, including flagellates and very small phytoplankton.

Microplankton

Plankton in the size category of $20-200\,\mu m$, with diatoms as a common example.

Mesoplankton

Plankton in the size category of $200\,\mu m-2\,cm$, such as copepods.

Macroplankton

Plankton in the size category of $2\,cm+$ which includes organisms like jellyfish.

Wild capture fisheries

The harvest of aquatic organisms from their natural environments, including commercial, recreational, and subsistence activities.

Sustainable Fishing (MSC Definition)

Fishing that leaves enough fish in the ocean, respects habitats, ensures livelihoods, prevents overfishing, and maintains biodiversity.

Fish Otoliths

Structures in fish used by scientists to determine age, growth, and location stories.

IUU Fishing

Illegal, unreported, and unregulated fishing.

Advection

The transport of organisms, such as swirling plankton, by oceanographic features.

Megascale

Oceanographic patterns at a spatial scale of $\ge 3000\,km$, resembling major oceanic circulations.

Macroscale

Oceanographic features at a spatial scale of $1000-2999\,km$, such as upwelling, the Leeuwin Current, or the East Australian Current.

Mesoscale

Oceanographic patterns at a spatial scale of $100-999\,km$, often involving pinched-off meanders or large freshwater plumes.

Ekman Transport

The movement of water away from the shore caused by wind, which is a primary mechanism for upwelling.

Aquaculture

The farming of aquatic organisms in controlled environments, involving intervention in the rearing process to enhance production (e.g., stocking, feeding).

Domestication (Aquaculture)

The process where the life cycle of a species is fully closed in captivity; aquatic species are being domesticated at a rate of $3\%$ p.a.

Integrated Multi-Trophic Aquaculture (IMTA)

A system producing two or more functional groups trophically connected by nutrient flows, where waste from one species becomes a resource for another.

eDNA (Environmental DNA)

DNA traces left by organisms in the environment through faeces, urine, mucus, or dead tissue, used to quantify abundance without seeing the host.

Anisogamy

A condition where there is a difference in the size of gametes (egg vs. sperm).

Macrogamete

The larger, energy-rich gamete (female) providing stored energy and haploid genetic instructions.

Microgamete

The smaller, motile gamete (male) providing motility mechanisms and haploid genetic instructions.

Gonochronists

Organisms that have separate sexes.

Protogyny

A form of sequential hermaphroditism where an individual changes sex from a functional female to a functional male.

Protandry

A form of sequential hermaphroditism where an individual changes sex from a functional male to a functional female (e.g., Barramundi).

Planktotrophic larvae

Larvae from small eggs with little yolk reserves that must feed in the plankton and have potential for long-distance dispersal.

Lecithotrophic larvae

Larvae produced in low numbers with large yolk reserves that do not feed in the plankton and have short dispersal distances.

Direct development

A development type involving little or no dispersal by young, often involving metamorphosis within the egg or ovovivipary.

Ucrit

Critical swimming speed, used as a measure of locomotor capacity in fish larvae athletes.