131
in the bottom (Colakoğlu and Tokac 2017). The type of dredge that is used varies
depending on whether the sea bottom consists of mud, sand, pebble, rocks, or boulders. The dredge consists of a heavy metal frame, about 3.5 m wide, attached to a
bag made from steel rings (10–12 cm diameter) with interconnecting chains as reinforcement. On smooth terrain the bag may last several trips, but on rough ground it
may not even last one trip. Divers are limited to working in shallow waters (<30 m
depth) because of safety and economic considerations. Usually teams of two to
three divers operate from a small boat with an outboard engine. Each diver systematically covers lucrative spots within a given area, the choice invariably based on a
prior working knowledge of the fishing ground (Gosling 2015).
3.1.1 Mussels
3.1.1.1 General Information About Mussels
Mussel is the common name used for members of several families of bivalve molluscs, from saltwater and freshwater habitats. The word “mussel” is frequently used
to mean the bivalves of the marine family Mytilidae, most of which live on exposed
shores in the intertidal zone, attached by means of their strong byssal threads
(“beard”) to a firm substrate. The common name “mussel” is also used for many
freshwater bivalves, including the freshwater pearl mussels. Freshwater mussel species inhabit lakes, ponds, rivers, creeks, canals, and they are classified in a different
subclass of bivalves, despite some very superficial similarities in appearance
(Wikipedia 2019a).
Mussels are widely used as bio-indicators to monitor the health of aquatic environments in both fresh water and the marine environments. They are particularly
useful since they are distributed worldwide, and they are sessile. These characteristics ensure that they are representative of the environment where they are sampled
or placed. Their population status or structure, physiology, behaviour, or the level of
contamination with elements or compounds can indicate the status of the ecosystem
(Wikipedia 2019a).
Biology of Mussels
The mussels are composed of two shells, clamped with very strong muscles, triangular front, oval and bilaterally symmetrical. The shell consists of anterior edge,
posterior edge, ventral edge, and dorsal edge. The front edge is very short, and the
shells are interlocked here. The exterior of the shell is in various shades of purple
and brown, while the interior is luster of mother of pearl. On the shells, there are
growth lines in the form of small elliptical circles. There is byssus that provides
clamping of mussels to dock walls, rocks, and all kinds of hard grounds. There are
about 150 byssus fibres in a medium size mussel (Alpbaz 1993).
3.1 Bivalves
in the bottom (Colakoğlu and Tokac 2017). The type of dredge that is used varies
depending on whether the sea bottom consists of mud, sand, pebble, rocks, or boulders. The dredge consists of a heavy metal frame, about 3.5 m wide, attached to a
bag made from steel rings (10–12 cm diameter) with interconnecting chains as reinforcement. On smooth terrain the bag may last several trips, but on rough ground it
may not even last one trip. Divers are limited to working in shallow waters (<30 m
depth) because of safety and economic considerations. Usually teams of two to
three divers operate from a small boat with an outboard engine. Each diver systematically covers lucrative spots within a given area, the choice invariably based on a
prior working knowledge of the fishing ground (Gosling 2015).
3.1.1 Mussels
3.1.1.1 General Information About Mussels
Mussel is the common name used for members of several families of bivalve molluscs, from saltwater and freshwater habitats. The word “mussel” is frequently used
to mean the bivalves of the marine family Mytilidae, most of which live on exposed
shores in the intertidal zone, attached by means of their strong byssal threads
(“beard”) to a firm substrate. The common name “mussel” is also used for many
freshwater bivalves, including the freshwater pearl mussels. Freshwater mussel species inhabit lakes, ponds, rivers, creeks, canals, and they are classified in a different
subclass of bivalves, despite some very superficial similarities in appearance
(Wikipedia 2019a).
Mussels are widely used as bio-indicators to monitor the health of aquatic environments in both fresh water and the marine environments. They are particularly
useful since they are distributed worldwide, and they are sessile. These characteristics ensure that they are representative of the environment where they are sampled
or placed. Their population status or structure, physiology, behaviour, or the level of
contamination with elements or compounds can indicate the status of the ecosystem
(Wikipedia 2019a).
Biology of Mussels
The mussels are composed of two shells, clamped with very strong muscles, triangular front, oval and bilaterally symmetrical. The shell consists of anterior edge,
posterior edge, ventral edge, and dorsal edge. The front edge is very short, and the
shells are interlocked here. The exterior of the shell is in various shades of purple
and brown, while the interior is luster of mother of pearl. On the shells, there are
growth lines in the form of small elliptical circles. There is byssus that provides
clamping of mussels to dock walls, rocks, and all kinds of hard grounds. There are
about 150 byssus fibres in a medium size mussel (Alpbaz 1993).
3.1 Bivalves