91
The catch ratio is a function of the abundance of lobster and catchability of the
gear. The unit of effort for lobster fishing is bait traps, and its ability to catch is
influenced by several factors related to lobster biology, the environment, mechanical design of traps, and fishing strategy (Drinkwater et al. 2006). Wind, which is one
of the environmental factors, is reported to be an important factor affecting the
catch rate. Winds from a certain direction provide good catch, while winds from the
opposite direction can reduce the catch rate (Drinkwater et al. 2006). On the other
hand, other researchers have reported the effect of temperature on catch rate. In a
study, it was determined that the monthly catchability coefficient of western rock
lobster (Morgan 1974) and American lobster (McLeese and Wilder 1958) had a
positive correlation with temperature and salinity.
Crayfish are caught using various active and passive catching methods. These
methods include hand-catching, bait-free traps, bait rods, nets, electro fishing and
diving. There is no single effective method under all circumstances. For this reason,
the characteristics of environmental conditions and sources of crayfish should be
taken into consideration in the selection of the appropriate fishing method (Ulikowski
et al. 2017).
Nutritive Composition of Lobsters
Lobsters, like other crustaceans, are important creatures with high protein and low
fat content in terms of nutritional value (Table 2.5). The chemical composition of
European lobster (H. gammarus) and American lobster (H. americanus) differed
according to body parts, sex, and species. While muscle and gonads are rich in protein, hepatopancreas is rich in fat; cholesterol and energy content (Barrento
et al. 2009).
Lobsters are rich in copper, selenium, zinc, phosphorus, vitamin B 12 , magnesium, and vitamin E (Ayanda et al. 2018). The contents of vitamin A, Vitamin D 2 ,
Vitamin D 3 , and alpha tocopherol for A. Leptodactylus were reported as 0.43, 0.54,
0.26, and 1.19 μg/g, respectively (Harlioglu et al. 2012).
Crustaceans, shrimps, crabs, and lobsters are considered important sources of
heavy metals for consumers. It has been discovered that they have high sensitivity
to metals and can accumulate high concentrations of metal from their environment.
These elements are ultimately transferred to higher levels of the food chain and
finally to human beings.
The level of fatty acids varies between species. In one study, H. americanus was
found to contain more MUFA, especially eicosenoic acid and less n-6 fatty acids
than H. Gammarus. The main n-3 PUFA in all tissues were eicosapentaenoic (EPA,
20:5n-3) and docosahexaenoic (DHA, 22:6n-3) (Barrento et al. 2009). Lipids of
Norway lobster (N. norvegicus) contain 42–48% PUFA, 26–35% MUFA and
23–27% SFA (Rosa and Nunes 2004). Samiee et al. (2017) found that the dominant
omega-3 fatty acids in liver and muscle tissues of Panulirus homarus are
Eicosapentaenoic acid (24.32–25.17%) and Docosahexaenoic acid (4.62–6.32%).
Second dominant fatty acid was palmitic acid (19.18–22.14%). Baghlani et al.
2.3 Lobsters
The catch ratio is a function of the abundance of lobster and catchability of the
gear. The unit of effort for lobster fishing is bait traps, and its ability to catch is
influenced by several factors related to lobster biology, the environment, mechanical design of traps, and fishing strategy (Drinkwater et al. 2006). Wind, which is one
of the environmental factors, is reported to be an important factor affecting the
catch rate. Winds from a certain direction provide good catch, while winds from the
opposite direction can reduce the catch rate (Drinkwater et al. 2006). On the other
hand, other researchers have reported the effect of temperature on catch rate. In a
study, it was determined that the monthly catchability coefficient of western rock
lobster (Morgan 1974) and American lobster (McLeese and Wilder 1958) had a
positive correlation with temperature and salinity.
Crayfish are caught using various active and passive catching methods. These
methods include hand-catching, bait-free traps, bait rods, nets, electro fishing and
diving. There is no single effective method under all circumstances. For this reason,
the characteristics of environmental conditions and sources of crayfish should be
taken into consideration in the selection of the appropriate fishing method (Ulikowski
et al. 2017).
Nutritive Composition of Lobsters
Lobsters, like other crustaceans, are important creatures with high protein and low
fat content in terms of nutritional value (Table 2.5). The chemical composition of
European lobster (H. gammarus) and American lobster (H. americanus) differed
according to body parts, sex, and species. While muscle and gonads are rich in protein, hepatopancreas is rich in fat; cholesterol and energy content (Barrento
et al. 2009).
Lobsters are rich in copper, selenium, zinc, phosphorus, vitamin B 12 , magnesium, and vitamin E (Ayanda et al. 2018). The contents of vitamin A, Vitamin D 2 ,
Vitamin D 3 , and alpha tocopherol for A. Leptodactylus were reported as 0.43, 0.54,
0.26, and 1.19 μg/g, respectively (Harlioglu et al. 2012).
Crustaceans, shrimps, crabs, and lobsters are considered important sources of
heavy metals for consumers. It has been discovered that they have high sensitivity
to metals and can accumulate high concentrations of metal from their environment.
These elements are ultimately transferred to higher levels of the food chain and
finally to human beings.
The level of fatty acids varies between species. In one study, H. americanus was
found to contain more MUFA, especially eicosenoic acid and less n-6 fatty acids
than H. Gammarus. The main n-3 PUFA in all tissues were eicosapentaenoic (EPA,
20:5n-3) and docosahexaenoic (DHA, 22:6n-3) (Barrento et al. 2009). Lipids of
Norway lobster (N. norvegicus) contain 42–48% PUFA, 26–35% MUFA and
23–27% SFA (Rosa and Nunes 2004). Samiee et al. (2017) found that the dominant
omega-3 fatty acids in liver and muscle tissues of Panulirus homarus are
Eicosapentaenoic acid (24.32–25.17%) and Docosahexaenoic acid (4.62–6.32%).
Second dominant fatty acid was palmitic acid (19.18–22.14%). Baghlani et al.
2.3 Lobsters