Will
imposing limits on fishing in the Baltic Sea guarantee the restoration of the
harbor porpoise population?
By Bohdan
Draganik
Translation
provided by Aleksandra Cegielska-Johnson
Introduction
The
manager of a deep-sea fishing firm, a man with great knowledge of the fishing
industry, tried to convince me in the seventies that turning in detailed FAO
fishing statistics is pointless, since in the end they will be used against the
Polish fishing industry. To express it tritely, “these statistics will invite
competing fishing fleets or provoke an expansive action on behalf of other
coastal countries”. Judging from the present condition of Polish deep-sea
fishing it is easy to see who was right. The occupation of fishing promotes the
following attitude: “catch the most you can, but do not senselessly destroy”.
As a consequence of such an attitude, fishermen put their trust in the
institutions involved with the protection of marine life hoping that their
causing the accidental death of animals (not being targeted by fishing) will not
be viewed as breaking either binding regulations nor traditional ethical norms.
Therefore, fisherman are ready to continue informing the appropriate officials
about such mishaps. In the past, their submitted fishing reports and personal
interviews were our sole source of information regarding the number of
accidentally caught marine mammals, birds and sturgeons.
Population of Harbor Porpoise
in the Baltic Sea
In
the previous issue of MPR 1(25), Kuklik and Skora presented current actions
being taken in order to preserve the population of the harbor porpoise
inhabiting the Baltic Sea. I would like to emphasize that the term “population
inhabiting the Baltic Sea” is not equivalent with the notion of the
general population of Baltic harbor porpoise. The term “population” at its
origin is related exclusively to a group of people. Later this term as used in
ecology was extended and presently refers to groups of individuals belonging to
any species of flora or fauna capable of free intercrossing who coexist in a
specific area. The branch of knowledge involving fishing uses two terms in order
to define the status of groups of animals co-inhabiting a specific area:
“population” and “pod”. Population refers to an isolated group of
individuals belonging to the same species and occurring in a defined area. Pod
refers to a group of individuals with common genetic features but distinct
enough to form a self-maintained system suitable as a utilized object.
Differentiation between these two terms regarding the harbor porpoise seems
important for approaching a protective policy. Consequently, the harbor porpoise
is not endangered as a species, however according to the experts at ASCOBANS the
pod of Baltic harbor porpoise is facing such a danger.
I do not
have any reason to question the data published in scientific journals describing
the genetic and morphometrical differences between the harbor porpoise caught in
the Baltic Sea and those from the North Sea and the Skagerrak.
However, I find the reported uneven distribution of Baltic harbor
porpoise rather strange particularly given that its highest density overlaps
within the most western located area of its occurrence (the Statistic Subarea
#23). It also seems worth mentioning that, Wand and Berggeren in their paper
published in 1997, by using the
newest genetic methods proved that the Baltic sup-population of harbor porpoise
is distinct from the sub-population of Skagerrak and Kattegat. In the summary of
their paper, the authors stated: “Despite the existing evidence showing a
difference between these sub-populations ( Baltic Sea, Skagerrak, Kattegat and
Norwegian Sea -B.D.), the boundaries of their settlement remain unknown and have
to be identified to ensure their effective protection”. The majority of
participants at the Jastarnia meeting, including the author of this article,
were not introduced to the paper by Wang and Berggeren as ASCOBANS experts
tactfully did not touch the issues discussed in this paper.
The
plan for restoration of harbor porpoise in the Baltic Sea.
The
meeting in Jastarnia as described by Kuklik and Skora in their article was one
of many steps taken by ASCOBANS experts towards developing a plan for the
restoration of the harbor porpoise in the Baltic Sea. The final goal of their
plan will be to restore the number of harbor porpoise to 80% of its habitat
capacity. Unfortunately, the organizers of the meeting in Jastarnia did not
precisely define the principle of habitat capacity (presumably in the Baltic Sea).
The vary idea of habitat capacity is often used in ecology as a parameter in
models referring to both intra-species and inter-species rivalry. I would like
to quote the author of, in my opinion, one of the best textbooks about life of
the biosphere. According to this author, the parameter K which signifies the
habitat’s capacity is useful in equations describing the mathematical model
for rivalry. However, the same parameter outside of the equation is difficult to
interpret and therefore should not be used as an independent tool in measuring
resources. Based on what was presented above and on the limited knowledge
regarding quantity of the herd of harbor porpoise in the Baltic, the question
arises what the earlier described 80% of the habitat capacity should be related
to. It was estimated by the authors of one of the papers by using the model of
Potential Biological Production, that the temporary goal of harbor porpoise
conservancy efforts (which is 80% of habitat capacity) can be accomplished only
by limiting the catch to 2 or less individuals per year. Data from that paper
was recognized by ASCOBANS experts
as a base for a plan for the restoration of the harbor porpoise population in
the Baltic.
Members
of scientific, fishing, and maritime administrations and the environmental
protection circles (including the author of this article) were represented at
the meeting in Jastarnia. In my view, this meeting was not properly arranged.
The two major issues of the meeting (evaluation of the number of harbor porpoise
currently inhabiting the Baltic and their death rate caused by the Baltic
fishing industry) were presented to the participants of the meeting merely
verbally with no documentation offered to support the presented issues.
Much later the participants were presented via E-mail with the article
based on the assumption that two separate populations of harbor porpoise coexist
in the Baltic (first populating among others the Skagerrak and Kattegat areas,
second populating the Baltic Sea). The same article also offered some data from
the analysis of different options for preservation of the harbor porpoise
population in the Baltic Sea. Results of simulating calculations presented in
this article were based on assumptions whose consistency with real conditions is
hard to verify. These results indicate however that reaching the goal proposed
by ASCOBANS and restoring the population of harbor porpoise to the level of 80%
of its habitat capacity will take over 100 years. Therefore, authors of this
paper stipulate to use available finances to introduce replacing fishing
procedures or modify currently used fishing tools to reduce the accidental catch
of Baltic harbor porpoise to a minimum, rather than invest large sums of money
in monitoring its industrial catch. In the light of this proposal, I still do
not see a solution to the vicious circle of assumptions that the proposed limits
in fishing are based on and which in turn will cause irreversible social and
economic consequences.
How
to reduce the number of entwining nets used in cod and salmon fishing
responsible for the high death rate of harbor porpoise remained the
dominating topic debated during the meeting. Approximately 600 harbor porpoise
individuals currently inhabit the Baltic Sea, as estimated by Swedish expert
Berggeren, however in the view of the rules of statistics the actual number can
vary from 200 to 3300. To quote Kuklik and Skora (from Polish red book of
animals, Vertebrates, 2001, PWRiL), “We do not have specific data for the
Polish zone of the Baltic Sea. On the average 5 to 6 but less than a dozen of
the individuals can be observed in this area every year”.
According to experts, accidental catches in fishing nets is greatly
responsible for the wasting of the harbor porpoise in the Baltic, however no
documents were produced in recent years to prove this claim. On the contrary, a
larger number of Baltic harbor porpoise were observed in recent years as
compared with the 6-th and 7-th decade of the last century.
The
organizers of the meeting must be credited with delivering in time to all
participants the materials describing the United States’ approach to harbor
porpoise conservancy in the waters under their jurisdiction. The reading of the
presented materials clarifies their reason for the conservation of the harbor
porpoise population and explains its efficiency and acceptance by the American
fishing community. Firstly, all the conservation efforts in the United
States were preceded by an analysis of the reports prepared by independent
observers and offering information about the number of harbor porpoise in the
habitat and the number of animals which perished in fishing nets. Secondly, the
quantity of the permissible catch of these animals was determined based on a
comprehensible algorithm. The final decision regarding potential fishing
restrictions was based on the ratio between the estimated number of harbor
porpoise inhabiting the zone of interest and the estimated quantity of
permissible catch. The final proposal for the potential restrictions was based
on a consensus worked out by a group consisting of all the parties involved,
including administration, academic centers, scientific institutes and members of
commercial and recreational fishing. If by any chance the consensus among
participants was not achieved, the Secretary of Commerce will step in and
determine the means for fishing supervision. It will illustrate the scope of the
matter under discussion in the United States by presenting some numbers. As it
was estimated in Maine, about 2100 harbor porpoise individuals are lost to
entwine fishing nets each year. The permissible catch was appointed to 438
individuals. Therefore the final objective of the proposed fishing regulation
was to decrease the accidental catch to less than 438 individuals per year.
If
the Polish government as a consequence of a request by an appropriate
administrative office would ratify an international agreement, then the same
office ought to define the parties responsible for fulfillment of that agreement
and for covering the resulting cost. To date, research conducted by the Maritime
Station of the University of Gdansk, due to limited funds, was restricted to
morphometric analysis and establishing levels of toxic substances in harbor
porpoise corpses either found on the beaches or delivered by fishermen. I find
it only appropriate to appeal to fishermen to continue their team-work
with Dr. Skora and his group from the station, rather than dreaded
proposed limits in fishing using cod nets or the proposed replacement of nets
with trap equipment in cod fishing. Continued team-work with Dr. Skora’s group
will be for the best, not only for the fishing community, but also for the
population of the harbor porpoise. Undoubtedly, we should not expect other
countries to financially assist Polish scientist in their efforts to appraise
the number of harbor porpoise individuals inhabiting the Polish zone of the
Baltic Sea. Conducting such research is obligatory for each signatory of this
international agreement. On the other hand such an appraisal does not have to
constitute an annual obligation and to execute it once every few years seems to
be sufficient and conducting them in collaboration with scientists from other
countries should be encouraged. The final responsibility for this research
should however solely rest with Polish scientists and by using the appropriate
administrative office none but them should present the data and determine
potential fishing limitations imposed on the Polish zone of the Baltic Sea. The
proposition of any limitations should not however be derived from British or
Canadian experts regardless of their worldly renown. Data resulting from
observations and accepted by all involved parties should fashion the research,
but only allowing all involved
parties to participate in the observations will make it possible.
Conditions for
successful restoration of harbor porpoise population in the Baltic
The
member of the Swedish fishing community present at the meeting in Jastarnia
expressed his opinion: “As far as we can see from the fishermen’s point of
view there is no need for introducing new rules in fishery to protect a not
existing population of porpoises”. In my view, however, such a position of
ignoring the problem is not acceptable. The authors of the plan for restoration
of harbor porpoise population in the Baltic stated: “There is plenty of
evidence that the accidental catch by fishing tools not only is responsible for
the decrease in the population of the harbor porpoise, but also prevents the
restoration of this population”. The authors quote many articles to confirm
their thesis, among them articles with data not qualified to be used in the
analysis considering the reasons behind the death rate of the harbor porpoise.
Blaming the fishing industry needs to be supported by hard evidence or at least
disclosure of resources supporting this claim. This is the only way to avoid
being suspected of manipulation. It would be hard to shake the opinion that
every additional net used by the fishing industry increases the risk of higher
death rates in the population of the harbor porpoise. Similarly, every newly
registered car in the country increases the risk of higher death rates caused by
cancer or allergens. Nobody of a sane mind would suggest however to replace
gasoline powered vehicles with scooters or bicycles. It would be hard to prove
that all the harbor porpoise individuals found on the beach died exclusively
from wounds inflicted by fishing nets rather than caused by damage to their
hydro-locating system inflicted by noise or mechanical sources like propellers
as well as explosives, pollution, or injuries caused by collisions with sailing
crafts.
Along
the USA coast lines, the number of harbor porpoise individuals accidentally
caught in nets was reduced after an implementation of the obligatory use of
acoustic scaring devices “pingers”. During the meeting in Jastarnia,
ASCOBANS experts recommended the implementing of regulations requiring the
Polish fishing community to use similar devises. However, as rightly postulated
by Kuklik and Skora, Polish fishermen can not bear the costs of installing these
acoustic devices on the nets in case such an obligation should be enforced. To
determine who should bear a cost of this “fishing regulating” device is
important but is also significant to consider if such a device will assure
expected results. It is possible that a common use of this device will cause
animals to get accustomed to it or even recognize it as a invitation to dinner.
Any malfunction to these devices
can cause an increase in the accidental catching of harbor porpoise as a result
of attracting them to the zone obstructed by nets but viewed “free” by
animals. As acknowledged by ASCOBANS experts, the possible effects of
introducing “pingers” to Baltic fishing industry are unforeseeable since the
number of accidental catch is very low.
During
the meeting in Jastarnia, a special form for compilation presently existing
fishing expenditures for net fishery was designed. Even as so many questions are
emerging, for example; why ASCOBANS experts overlooked the involvement of
herring nets in spite of the fact that one of the experts told me he had
personally seen harbor porpoise being caught in these nets. Moreover, how the
area requiring special attention regarding evaluation of the number of entwine
nets was defined and restricted to eastern longitude 21o east and
northern latitude 56o 30' north. How such a precision in harbor
porpoise distribution in the Baltic Sea was accomplished, and yet experts from
Finland participating in the meeting confirmed the presence of these animals
along the coast of Finland.
From
the documents presented to the meeting participants, I have learned that Polish
and Swedish fishing industry operating on the Baltic Sea eliminates 7 harbor
porpoise individuals every year. On the other hand, a Danish fishery operating
on the North Sea and the Baltic Sea eliminates 7000 individuals according to the
findings received by extrapolation of the recorded data. Yet I am not aware of
any restrictions of fishing expenditure in the Danish fishery based on entwine
nets.
During
the meeting in Jastarnia, the necessity of cataloging all of the entwine nets
currently used by Baltic fishing industry was recognized. This idea can be
proven successful and bring credible data only if the employed unit for fishing
expenditure will be adequate. Knowing however the specificity of Baltic fishing
industry, such as unlike forms of registering fishing expenditure used in
different Baltic countries, I doubt the success of the whole undertaking.
Maybe
instead of restricting the activities of the branches of the fishing industry
being blamed for the high death rate within the population of the harbor
porpoise, one should develop other measures to reduce this high death occurrence.
The number of used nets and the allowed distance between set nets are closely
regulated by legal documents. Even if the fishing operations with use of entwine
nets undoubtedly constitute the biggest danger to the population of the harbor
porpoise, then we possibly should start first with establishing to what extent
the “empty space” between set nets is effective and how well executed are
the existing regulation. The very same preservation approach is proposed by
Kuklik and Skora:”......to maintain the existing species protective status,
but also try to improve the execution of the existing law regarding the
preservation of nature, including complying with statutory demands of the Bonn
Convention. Control over technic and strategy of fishing should be overall
improved with regard to its potential endangerment of the harbor porpoise
population (from Polish red book of animals, Vertebrates, 2001, PWRiL). I dare
to claim that if properly financed
the existing services overseeing the Polish fishing industry are capable of
assuring the well being of this industry in the interest of the population of
the harbor porpoise occasionally inhabiting the Polish zone of the Baltic Sea.
In conclusion, I wish that people exercising control over the Polish fishery on
the Baltic and the protection of the harbor porpoise will consider several facts
before they continue their work. For a start, the harbor porpoise species is not
in danger of extinction (on the contrary it received the status of a species so
far not showing signs of regression in its population) neither being
particularly rare. The North Sea alone has a population of 340 thousands. On the
other hand, the western sturgeon (Acipenser sturio L.) is considered a
vanished species and was protected in Poland by law since 1936. After WWII,
about 10-15 members of this species were accidentally caught in nets in the
Polish zone of the Baltic and yet it did not occur to anyone to shut down the
Polish fishing industry. While I do recognize the role of Polish fishery in the
national economy, I do not consent to its spurious status reserving the
exclusive right to the resources of the sea. After all, we are indebted to
fishery for the progress of the knowledge about sea life and development of
applied ecology. Anyone proposing any restrictions toward access to these
resources should first produce strong arguments other than “preservation of
biological diversity” and “achieving desirable harbor porpoise population
size in 109 years”. There is no doubt about current surplus in fishing
expenditure in the fishing industry and its need for adjustment in order to
accommodate the current reproductive rate of the fish population. It should be
preceded by defining the size of expenditure surplus and plan for its reduction.
Restoring the population of the harbor porpoise should not be in my opinion
exposed as a reason for introduction of any restrictions to the Baltic fishery.
The erosion of trust of Polish fishermen and the decrease in credibility of
numbers of animals accidentally caught in fishing nets could be the sole result
of such action.
Bohdan
Draganik
Sea
Fishery Institute
Gdynia
- Poland
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