Ocean Energy Resources 1
Ocean Habitat (I)
10-03-2014
Teresa Simas ( teresa@wavec.org
)
1

Ocean Habitat I (10-03-2014: 2pm)
1.1 Important definitions
1.2 Factors influencing ocean habitat distribution
1.3 Ocean zonation
1.4 The coastal zone
Ocean Habitat II (11-03-2014: 9 pm)
2.1 Habitat characterisation
2.2 Environmental issues to consider during site selection
2.3 Ocean habitat assignment
Ocean Habitat III (11-03-2014: 10 pm)
3.1 Descriptors of ocean habitat species
3.2 Ocean habitat communities
2

1. Important definitions
– Habitat
– Community
– Ecosystem
2. Factors influencing ocean habitat distribution
– Abiotic factors
– Biotic factors
3. Ocean zonation
– Ocean biomes
– Ocean life zones
4. The coastal zone
– Type of habitats
– Habitats’ protection: regulation
– Examples of marine protected habitats
3

1) Important definitions
The place where an organism lives
Spatial
Factors relating to units of distance or volume
A habitat can be a place, some location on earth which can vary with
• Latitude
• Longitude
• Depth
Temporal
Factors relating with units of time
A particular point in time: certain conditions of a given period of time that define a habitat for that particular organism
4

1) Important definitions
- Coral reefs
- Rocky shores
- Sandy beaches
- Wetlands (mangrove forests, salt marshes)
- Abyss
- Sea mounts
- Rocky seabeds
- Coastal sand banks
- Water column (phytoplankton zooplankton)
- Artificial reefs (e.g. wave energy devices, moorings of wind offhore fixed turbines)
5

1) Important definitions
- Migration destinations (seabirds marine mammals, fish)
- Fish breeding and nursery grounds
- Primitive earth habitats
6

1) Important definitions
Habitat is not only defined as spatial and temporal sense
Community
A group of organisms living and interacting with each other
Ecosystem
A community of organisms and the non-living environment with which they interact
7

2)
Geological
It’s easier to identify habitats in earth (deserts, mountains, vales, beaches, grasslands); but in the ocean there are more subtle thinks: e.g temperature, pressure, how the water moves
Biological
There are several important factors determining where
(spatial) and when
(temporal) a particular organism lives
Physical
Chemical
The ocean is threedimensional and constantly in motion
8

2)
The chemical and physical environmental factors (nonliving components) in ecosystems
• Temperature
• Light availability
• Pressure
• Chemical conditions (pH, nutrients, O2, CO2)
• Turbulence (or water circulation conditions)
• Type of or cover
Created by a living thing or any living component within an environment in which the action of the organism affects the life of another organism
• Predation: trophic relations between species
• Competition between organisms and species
• Symbiosis
• Disease agents
9

• The ocean can be sliced vertically (by depth) or horizontally (by latitude or longitude)
• Vertical layers are called vertical ocean life zones
• Horizontal regions are called Biomes (from the
Equator towards the poles)
• Life zones and biomes are convenient to define ocean habitat but probably overgeneralized
Biomes are more applicable to terrestrial habitats but some oceanographers are giving stride to define them also
10

3) Ocean biomes (horizontal regions)
Regions of the sea surface vary from the Equator to the Poles according to:
• Sunlight availability (day length)
• Water temperature
• Currents
Ocean biome
A region of the world ocean characterised by a particular set of physical and chemical conditions that promote a particular set of phytoplankton
• Include permanently (tropical) and seasonally stratified (subtropical) regions
• Upwelling regions
• Downwelling regions
• Subpolar regions
• Marginal ice zone
Ocean biome is a relatively new concept, so its definition is likely to be refined or changed as oceanographers learn more about the couplig between physical, chemical and biological processes
11

3) Ocean biomes (horizontal regions)
Eq-D: equatorial downwelling
Eq-U: equatorial upwelling
ST-PS: subtropical permanently stratified
ST-SS: subtropical seasonally stratified
LL-U: Low latitude upwelling
SP: subpolar
Ice: marginal ice zone
12

3) Ocean biomes (horizontal regions)
Upwelling and downwelling phenomena
Upwelling is the upward flow of deeper water towards the surface
Downwelling is the downward flow of surface water towards the bottom
Generates the most productive regions of the world ocean (most productive fisheries)
Upwelling is caused by the Ekman transport:
Wind blowing on the sea surface causes the water to move 90 degrees to the right, in the Northern hemisfere, or to the left in the southern hemisfere
13

3) Ocean biomes (horizontal regions)
Equatorial upwelling phenomena
Trade winds of the world
The wind blows from east to west; the water moves 90 degrees to the right of the wind direction, in the north hemisphere and 90 degrees to the left of the wind direction, in the southern hemisphere; the water in the surface which is diverging is replaced by colder and nutrient enriched water.
14

3) Ocean biomes (horizontal regions)
Equatorial upwelling phenomena
15

3) Ocean biomes (horizontal regions)
Coastal upwelling
16

3) Ocean biomes (horizontal regions)
Downwelling phenomena
• The wind blows from the south and Eckman transport directs water onshore
(slope of water towards the shore) which sinks surface water (movement of surface water deeper)
• Unlike upwelling, the downwelling phenomena shuts down primary productivity
Termohaline circulation: http://www.youtube.com/watch?v=3niR_-Kv4SM
17

From the surface waters to the deepest waters
Seabed (bottom) from inshore to offshore
18

3) Ocean life zones (vertical zones)
• Epipelagic
• Mesopelagic
(twilight zone)
• Bathypelagic
• Abyssopelagic
• Hadalpelagic
19

3) Ocean life zones (vertical zones)
Neritic (or coastal) zone
Influenced by terrestrial processes
Oceanic (open ocean) zone
Beyond the influence of terrestrial processes
Important definitions; these are the zones where organisms live
20

4) The coastal (neritic) zone
Subject to sunlight, winds, waves, tides, air-sea exchanges of energy
(wind and sunlight) and matter
(note that some of these processes extend deeper)
The lower limit of this zone is defined at the depth where the available light is 1% of the light. It is defined as euphotic zone. The euphotic zone is the depth until which the photosynthesis occurs or the deepest depth of light penetration
Physically and chemically this zone is highly variable and dynamic over spatial and temporal scales
Most part of the knowledge on ocean is on the coastal zone
Most part of the human activities are developed in the epipelagic zone including renewable energy
21

4) The coastal (neritic) zone
A number of different habitats in the coastal zone
• Sand banks
• Reefs
• Coral reefs
• Beaches
• Saltmarshes
• Magrove forests
There are several regulatory frameworks that protect such habitats:
• International conventions
• EU Directives
• National legislation on Marine
Protected Areas
22

5) Marine habitats protection
Habitats Directive 79/409/EEC - Reefs (habitat 1170)
“Submarine, or exposed at low tide, rocky substrates and biogenic concretions 1 , which arise from the seafloor in the sublittoral zone but may extend into littoral zone where there is an uninterrupted zonation of plant and animal communities. These reefs generally support a zonation of benthic communities of algae and animals species including concretions, encrustations and corallogenic concretions.”
1 Solid, massive structures which are created by accumulations of organisms, usually rising from the seabed, or at least clearly forming a substantial, discrete community or habitat which is very different from the surrounding seabed
23

5) Marine habitats protection
Habitats Directive 79/409/EEC – Sandbanks which are slightly covered by seawater at all times (habitat 1110)
“Sublitoral sandbanks, permanently submerged.
Water depth is seldom more than 20m below Chart datum.
Non-vegetated sandbanks or sandbanks with vegetation belonging to the Zostera marina and Cymodocea nodosae.”
24

5) Marine habitats protection
Habitats Directive 79/409/EEC – Submarine structures made by leaking gases
(habitat 1180)
“Spectacular sub-marine complex structures, consisting of rocks, pavements and pillars up to 4 metres high. These formations are due to the aggregation of sandstone by carbonate cement resulting from microbial oxidation of gas emissions, mainly methane. The methane most likely originated from microbial decomposition of fossil plant materials. The formations are interspersed with gas vents that intermittently release gas. These formations shelter a highly diverse ecosystem with brightly coloured species.”
25

5) Marine habitats protection
Habitats Directive 79/409/EEC – Submerged or partially submerged caves (habitat 8330)
“Caves situated under the sea or opened to it, at least at high tide, including partially submerged sea caves. Their bottom and sides harbour communities of marine invertebrates and algae.”
26

http://www.youtube.com/watch?v=8VOabiuIp_Y
27