Page 150 - (DK) Ocean - The Definitive Visual Guide

148 SHALLOW SEAS

ATLANTIC OCEAN WEST ATLANTIC OCEAN NORTHEAST Strong tidal currents flow through the bearing currents that are essential for
Sound of Barra, and its clear, shallow healthy growth. Eelgrass also grows in
Laguna de Términos Sound of Barra waters and sandy sea floor provide an nearby brackish lagoons, together with
ideal habitat for the eelgrass Zostera the tasselweed Ruppia maritima, which
COASTAL TYPE Shallow COASTAL TYPE Island marina. The eelgrass beds, together is regarded by some scientists as a type
lagoon chain with sounds with beds of maerl (see p.245), are of seagrass. Forests of the kelp Laminaria
WATER TYPE Tropical WATER TYPE Cool home to many species of small hyperborea grow on rocks at the edges
PRIMARY VEGETATION PRIMARY VEGETATION animals. Such rich, current-swept of the sound, and these are home to
Seagrasses, seaweeds, Seagrasses, maerl, and communities in this part of Scotland abundant sea squirts and sponges.
and mangroves kelp are threatened by the building of rock
LOCATION In the southwest of the Yucatán Peninsula, LOCATION Between South Uist, Eriskay, and Barra, causeways across the sounds, which
Campeche State, Mexico Outer Hebrides, Scotland, UK cut off the nutrient-

SATELLITE VIEW, WITH LAGOON AT TOP
Two channels connect this sediment-
laden lagoon to the Gulf of Mexico,
while three rivers feed in fresh water,
producing a pronounced change in EELGRASS STANDS
salinity. The seagrasses Thalassia Healthy stands of eelgrass now thrive in
testudinum, Syringodium filiforme, and the current-swept sound. Almost 90
Halodule wrightii cover 29 percent of per-cent of western Europe’s eelgrass was
the lagoon. With 448 recorded animal lost to a wasting disease in the 1930s.
species, Términos is the most species-
rich of Mexico’s four large lagoons.

ATLANTIC OCEAN NORTHEAST together with part of Falmouth Bay,
have been designated as a European
Falmouth Bay marine Special Area of Conservation.
Beds of the eelgrass Zostera marina and
COASTAL TYPE Rocky maerl (see p.245) in the inlets are home
with inlets
to a wide variety of animals, including
WATER TYPE Cool the rare Couch’s goby.
PRIMARY VEGETATION On the wave-exposed rocky coasts
Laminaria hyperborea outside the inlets, the kelp Laminaria
kelp, eelgrass
hyperborea grows in dense forests that
LOCATION Southwest Cornwall, England, UK support many associated seaweeds and
animals. This kelp has a stiff stipe, which
The coastline of Falmouth Bay raises the frond off the sea bed and
includes two drowned river valleys means that the forest has developed
(rias), the Fal and Helford, which are well vertically. On the rock beneath
now long, sheltered sea inlets. Because the kelp, there is competition for space
of their rich marine life, these inlets, among anemones, sponges, and smaller
seaweeds, while other animals hide in
kelp holdfasts. The kelp stipes have
a rough surface and provide effective
attachment points for red seaweeds,
bryozoans, soft corals, and other types
of encrusting animals. On the fronds,
tiny blue-rayed limpets graze, and Saldanha Bay SOUTH ATLANTIC KELP FOREST
colorful sea slugs eat small hydroids
OCEAN ENVIRONMENTS limit in Europe. This kelp is similar to LOCATION Western Cape, South Africa kelps. It can grow as tall as 50 ft (15 m).
and lacy bryozoans.
ATLANTIC OCEAN SOUTHEAST
In deeper water, the kelp Laminaria
On the west coast of South Africa,
ochroleuca grows, close to its northern
sea bamboo is the largest of the local
COAST TYPE Rocky and
Laminaria hyperborea, but has a smooth
sandy bay with lagoon
is abundant in Saldhanha Bay. The
stipe on which little can grow. Two
WATER TYPE Cool
other kelps are found in the area, the
smaller split-fan kelp (Laminaria
currents
pallida) becomes dominant in deeper
sugar kelp (Laminaria saccharina), which
PRIMARY VEGETATION
has a crinkled frond, and furbelows
water. South Africa is famous for its
Kelp and eelgrass
diversity of limpets, and the kelp
(Saccorhiza polyschides), which has a
large, hollow holdfast and grows up
limpet Cymbula compressa is found only
on sea bamboo. Its shell fits neatly
to 13 ft (4 m) long in just one season.
around the stipe, where it grazes. The
The cold Benguela Current flowing
highly endangered limpet Siphonaria
northward along the west coast of
CORNISH KELP FOREST
compressa occurs only in the bay’s
South Africa brings nutrient-rich
This forest of Laminaria hyperborea kelp has
many different plants and animals living on the
Langebaan Lagoon, grazing on the
water that is ideal for kelp growth,
rocks beneath it, and on the kelp itself.
endemic eelgrass Zostera capensis.
and sea bamboo (Ecklonia maxima)