Rapp. Comm. int. Mer Médit., 36,2001
261
Introduction
Catch of Norway lobster,Nephrops norvegicus(Linnaeus, 1758), in
Croatian fisheries has a great commercial value. Its catch exceed total
catch of all crusctaceans, or all shells together, and even catch of some
commercially important fishes. The reason for that is its larger abun-
dance and dispersion in the Adriatic in relation to other crustaceans
and higher efficiency of fishing gear used for its catch. The area of its
distribution has been spread and could be found in commercial quan-
tities in many areas along the eastern Adriatic coast. Such area, among
others, is Velebit Channel where this research was conducted. Catch of
Norway lobster in Croatia, in last 10 years, varies between 500 to 600
tons per year (according to Croatian statistical data), but those data can
be consider quite underestimated, because the data for Norway lobster
are collected only from trawlers through their regular reports and none
from fisherman who are using pots for Norway lobster (1).
The aim of this paper was, according to obtained results such as
length structure, presence of immature specimens and sex ratio, to
evaluate in?uence of pots on population of Norway lobster in Velebit
Channel in order to protect it in the research area.
Material and methods
Research was conducted monthly during 1997. and 1998. in the area
ofVelebit Channel (northern Adriatic) on 7 general areas (see in Fig.
1). Fishing was carried out within 1NM from coast at depth between
70-80 m. The pot immersion time was usually one day except on occa-
sions when bad weather conditions didn’t allow lifting. Pots used for
this research were made of netting material with mesh size not lower
than 40 mm. Total of 12 077 pots was used and their dimension was
70x45x25 cm (Fig. 2). Pots were ordered in series of 20-40 pieces and
time of immerse of the one series was 5 - 10 min, while time of its lift-
ing was 35 - 45 min. Following parameters were determined for each
specimen: total length (L
t
) in cm, from tip of rostrum to posterior mar-
gin of telson, weight (in g) and sex. Fishing effort of pot was calculat-
ed according to average weight and number of specimens caught dur-
ing one immersion of pot.
Figure 1. The research area - Velebit Channel (
?
- stations).
Figure 2. Pot for Norway lobster used in Velebit Channel.
Results and discussion
The total length of Norway lobster ranged from 9.5 to 19.5 cm
(mean length = 12.5 ± 1.51 cm). Of the total specimens examined
(N=6212) 2653 (42.7%) were male and 3559 (57.3%) females. The
sex ratio was 1:1.34 in favour of female. Males were mostly dominant
in length classes 12.0-12.5 cm (29%), and females in length classes
11.5-12.0 cm (45.2%).
Fishing effort of pot was 19.76 g, while number of specimens 0.57
for one immersion, and those are the lowest values according to results
obtained by other authors for the same area and others in the eastern
Adriatic: 78 g for 36+44 m pots (3), 66.7 g for 36+38+40 mm pots
(4), and 96.87 for 36 mm, 71,86 for 40 mm, 64.90 for 44 mm pots (1).
According to recently finished research (2), the size of first maturi-
ty of Norway lobster in the eastern Adriatic was 9 cm, so it can be said
that no immature specimens were caught in pots, because a minimum
length of caught specimen was 9.5 cm. That means pots for catch of
Norway lobster are selective fishing gear and it can be consider as fish-
ing gear with no harmful in?uence on its population, because normal
reproduction of species has been allowed.
References
1 - Soldo A., Cetinic P. and Dulčic J., 1999. Catch of Norway lobster,
Nephrops norvegicus(L.), with lobster pot of different mesh size in the
eastern Adriatic. In: Swiniarski J. and Ceronik E. (eds.), Proceedings of
the International Symposium on Responsible Fisheries & Fishing
Techniques. Insko, Poland, pp. 281-287.
2 - Anonymous, 1999. Istrazivanje kompetitivnih odnosa izmedu ribolova
pridnenom povlačnom mrezom (koćom), vrsama za lov skampa i
jednostrukih mreza stajačica za ulov oslića u Velebitskom kanalu, s
posebnim osvrtom na populaciju skampa i oslića. Institut of
Oceanography and Fisheries, Split, 53 p.
3 - Obradovic J, Bačic G. and Slavica A., 1993. Utjecaj lova vrsa na
populaciju skampa Nephrops norvegicusL.Pomorski zbornik, 31: 627-
643.
4 - Homen Z., 1983. Analiza lova skampa (Nephrops norvegicusL.)
vrsama u Velebitskom kanalu. Morsko ribarstvo, 35/4: 121-123.
FISHING OF NORWAY LOBSTER, NEPHROPS NORVEGICUS(L.), WITH LOBSTER POT
IN THE VELEBIT CHANNEL (EASTERN ADRIATIC)
J. Dulcic, P. Cetinic, A. Pallaoro, A. Soldo*, I. Jardas, and M. Kraljevic
Institute of Oceanography and Fisheries, Split, Croatia - dulcic@izor.hr
Abstract
The effects of pots for Norway lobster on its population in Velebit Channel (northern Adriatic) were researched. It was found that pots have
got no damaging in?uence on its. population in the researched area.
Keywords: fisheries, Adriatic Sea
