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Shellfish Stocks and Fisheries Review 2020 Shellfish Stocks and Fisheries Review 2020 Review and Fisheries Stocks Shellfish
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Shellfish Stocks and Fisheries
Review 2020
An assessment of selected stocks
The Marine Institute and Bord Iascaigh Mhara
The data that underpins the advice provided in this book is collected under the Data Collection Framework, which is financed by the Irish government and the European Maritime & Fisheries Fund as part of the EMFF Operational Programme for 2014 -2020
i
Acknowledgement: Data presented in this report originates from a variety of sources including voluntary submission of information by fishermen, through core funded projects from the Marine Institute, and is part supported by the Irish government and the European Maritime and Fisheries Fund as part of the EMFF Operational Programme for 2014-2020
Photographs on cover by Jonathan White (Brown Crab – Cancer pagurus), Cian Luck (Crayfish – Palinurus elephas) and Macdara O Cuaig (Oyster – Ostrea edulis)
© Marine Institute and Bord Iascaigh Mhara 2020
Disclaimer: Although every effort has been made to ensure the accuracy of the material contained in this publication, complete accuracy cannot be guaranteed. Neither the Marine Institute, BIM nor the author accepts any responsibility whatsoever for loss or damage occasioned, or claimed to have been occasioned, in part or in full as a consequence of any person acting or refraining from acting, as a result of a matter contained in this publication. All or part of this publication may be reproduced without further permission, provided the source is acknowledged.
ISBN: 978-1-902895-69-7
1
CONTENTS
Table of Contents
Contents 1 Introduction ...... 4 2 Registered Fishing Fleet...... 5 2.1 Fleet structure ...... 5 2.2 Fleet capacity ...... 5 2.3 Fleet capacity transfer rules ...... 6 2.4 Vessels targeting Shellfish ...... 6 3 Shellfish Landings 2004-2020 ...... 10 4 Lobster ( ) ...... 12 4.1 Management advice ...... 12 4.2 Issues relevant to the assessment of the lobster fishery ...... 12 4.3 Management units ...... 13 4.4 Management measures ...... 13 4.5 Contribution of conservation measures to reproductive potential ...... 13 4.5.1 Implementation of the v-notched programme ...... 13 4.5.2 Relationship between numbers released and numbers at sea ...... 15 4.6 Reproductive potential ...... 17 4.7 Catch rates ...... 18 4.7.1 Seasonal and annual trends ...... 18 5 Crayfish ( ) ...... 20 5.1 Management advice ...... 20 5.2 Issues relevant to the assessment of the crayfish fishery ...... 20 5.3 Management units ...... 20 5.4 Management measures ...... 21 5.5 Catch composition ...... 21 5.6 Catch rates ...... 22 5.7 Tag recapture data ...... 23 6 Brown crab ( ) ...... 25 6.1 Management advice ...... 25 6.2 Issues relevant to the assessment of the crab fishery ...... 25 6.3 Management units ...... 26 6.4 Management measures ...... 26 6.5 Size distribution indicators ...... 26 6.6 Catch rates ...... 27 6.6.1 Annual trends ...... 27 6.6.2 Seasonal trends ...... 28 6.7 The Malin Stock ...... 29 6.7.1 Landings ...... 29 6.7.2 Assessment methods ...... 30 6.7.1 Interpretation of catch rate data ...... 31 6.7.2 Evolution of the fishery since the 1980s ...... 31 6.7.3 Questionnaire data on trends and attitudes ...... 33 7 Razor clam ( ) ...... 36 7.1 Management advice ...... 36
2
CONTENTS
7.2 Issues relevant to the assessment of the razor clam fishery ...... 36 7.3 Management units ...... 37 7.4 Management measures ...... 37 7.5 North Irish Sea ...... 38 7.5.1 Landings ...... 38 7.5.2 Survey 2020 ...... 40 7.5.3 Depletion corrected average catch assessment (DCAC) ...... 43 7.5.4 Stock biomass indicators ...... 44 7.5.5 Catch advice ...... 45 7.5.6 Economic indicators ...... 46 7.5.7 Ecosystem effects of the fishery ...... 46 7.5.8 Recent monitoring of infaunal deep burrowing bivalves ...... 47 7.6 South Irish Sea ...... 48 7.6.1 Landings ...... 48 7.6.2 iVMS fishing effort ...... 49 7.6.3 Survey data ...... 50 8 Cockle ( ) ...... 54 8.1 Management advice ...... 54 8.2 Issues relevant to the assessment of the cockle fishery ...... 54 8.3 Management units ...... 55 8.4 Management measures ...... 55 8.5 Dundalk Bay ...... 56 8.5.1 Biomass and landings 2007- 2020 ...... 56 8.5.2 Survey in 2020 ...... 56 8.5.3 Fisheries monitoring and exploitation rate ...... 58 8.5.4 Review of ecosystem effects ...... 59 9 Oyster ( ) ...... 65 9.1 Management advice ...... 65 9.2 Issues relevant to the assessment of the oyster fishery ...... 65 9.3 Management units ...... 66 9.4 Survey methods ...... 66 9.5 Inner Tralee Bay ...... 67 9.5.1 Stock trends ...... 67 9.5.2 Survey September 2020 ...... 67 9.6 Cill Chiaráin ...... 69 9.6.1 Stock trends ...... 69 9.6.2 Survey October 2020 ...... 69 9.7 Lough Swilly ...... 71 9.7.1 Native Oyster ( ) ...... 71 9.7.2 Pacific oyster ( ) ...... 73 10 Glossary ...... 76
3
INTRODUCTION
1 Introduction This review presents information on the status of selected shellfish stocks in Ireland. In addition, data on the fleet and landings of shellfish species (excluding and mussels) are presented. The intention of this annual review is to present stock assessment and management advice for shellfisheries that may be subject to new management proposals or where scientific advice is required in relation to assessing the environmental impact of shellfish fisheries especially in areas designated under European Directives. The review reflects the recent work of the Marine Institute (MI) in the biological assessment of shellfish fisheries and their interaction with the environment.
The information and advice presented here for shellfish is complementary to that presented in the MI Stock Book on demersal and pelagic fisheries. Separate treatment of shellfish is warranted as their biology and distribution, the assessment methods that can be applied to them and the system under which they are managed, all differ substantially to demersal and pelagic stocks.
Shellfish stocks are not generally assessed by The International Council for the Exploration of the Sea (ICES) and although they come under the competency of the Common Fisheries Policy they are generally not regulated by EU TAC and in the main, other than crab and scallop, are distributed inside the national 12 nm fisheries limit. Management of these fisheries is within the competency of the Department of Agriculture, Food and Marine (DAFM).
A co-operative management framework introduced by the Governing Department and BIM in 2005 (Anon 2005), and under which a number of fishery management plans were developed, was, in 2014, replaced by the National and Regional Inshore Fisheries Forums (NIFF, RIFFs). These bodies are consultative forums, the members of which are representative of the inshore fisheries sector and other stakeholder groups. The National forum (NIFF) provides a structure with which each of the regional forums can interact with each other and with the Marine Agencies, DAFM and the Minister.
Management of oyster fisheries is the responsibility of The Department of Communications, Climate Action and Environment (DCCAE) implemented through Inland Fisheries Ireland (IFI). In many cases, however, management responsibility for oysters is devolved through Fishery Orders or Aquaculture licences to local co-operatives.
The main customers for this review are DAFM, RIFFs, NIFF and other Departments and Authorities listed above.
4
SHELLFISH FLEET
Registered Fishing Fleet 2.1 Fleet structure The Irish fleet is, currently divided into 5 segments. Of these five segments (Aquaculture, Specific, Polyvalent, Beam Trawl and RSW Pelagic) two are broken into sub-segments, namely the Polyvalent and Specific Segments. Aquaculture vessels do not have fishing entitlements. Beam trawl vessels fish mixed demersal fish using beam trawls and RSW Pelagic are large pelagic vessels with refrigerated seawater tanks and target pelagic species. The Polyvalent Segment is divided into the following four Sub-segments;
(1) Polyvalent [Potting] Sub-segment; vessels of <12 m length overall (LOA) fishing exclusively by means of pots. Such vessels are also <20 Gross Tonnes (GT). Target species are crustaceans and whelk. (2) Polyvalent [Scallop] Sub-segment; vessels ≥10 m LOA with the required scallop ( ) fishing history. These vessels also retain fishing entitlements for other species excluding those listed in Determination No. 28/2018 (http://agriculture.gov.ie/fisheries/). (3) Polyvalent [<18 m LOA] Sub-segment; Vessels with fishing entitlements for a broad range of species other than those fisheries which are authorised or subject to secondary licencing as listed in Determination No. 28/2018 (4) Polyvalent [≥18 m LOA] Sub-segment; Vessels with fishing entitlements for a broad range of species other than those fisheries which are authorised or subject to secondary licencing as listed in Determination No. 28/2018.
The Specific Segment, which entitles vessels to fish for bivalves only, is divided into the following two Sub-segments; (1) Specific [Scallop] Sub-segment for vessels ≥10 m LOA with the required scallop ( ) fishing history (2) Specific [General] Sub-segment for all other Specific vessels irrespective of LOA.
2.2 Fleet capacity The total registered capacity of the Irish fishing fleet, as of December 2020, was 65,099 gross tonnes (GTs) and 1,996 vessels. The polyvalent general segment included 31,828 GTs and 1,390 vessels. The polyvalent potting segment had 329 registered vessels and 696 GTs while the bivalve (specific) segment had 1,261 GTs and 134 vessels. There were 10 beam trawl vessels, 11 scallop vessels over 10 m in the specific segment and 3 in the polyvalent segment and 23 RSW pelagic vessels (Table 1).
The total number of registered vessels in the fleet peaked in 2012 at 2,212 vessels which was 216 vessels more than in 2020.
In 2020 almost 74% of vessels in the fleet were under 10 m in length. These are typically open or half-decked traditional fishing vessels that fish seasonally in coastal waters. Ninety-four percent of polyvalent potting vessels were less than 10 m in length and all were under 12 m. Approximately 55% of the specific fleet of 134 vessels were under 10 m.
5
SHELLFISH FLEET
le er essels length teg r in e h seg ent the rish se ishing leet in eg ent ength teg r t l lt re 72 6 1 1 16 96 l lent ener l 1,028 151 57 20 134 1,390 l lent tting 311 18 329 e i i 74 52 6 2 134 R el gi 23 23 e i i ll s 3 1 7 11 l lent ll s 2 1 3 e r ler 10 10 t l
2.3 Fleet capacity transfer rules The following rules apply to the transfer of capacity within segments;
(1) Polyvalent capacity is privately transferable within its segment. Where an applicant for a polyvalent fishing licence has evidence of holding such capacity (a capacity assignment note) and has an approved fishing vessel then a fishing licence will be issued to such an applicant. Capacity attached to vessels under 18 m cannot be transferred to vessels over 18 m and vice versa. (2) Excluding the fisheries licenced by secondary authorisation the polyvalent capacity is not coupled to any given quota or entitlement. The capacity assignment note simply enables the vessel owner to complete the registration of a vessel. (3) In the case of fisheries fished with a permit or secondary licence the authorisation to fish such stocks is effectively coupled with the capacity if the capacity is transferred i.e. this transfer is essentially a transfer of track record in the particular fishery. Such entitlement is, however, also governed by TAC & Quota and any other policies or harvest control rules that might apply to those stocks. (4) Polyvalent potting capacity is not transferable within its segment other than to first degree relatives of the person to which the capacity was originally assigned. When it is no longer attached to a registered vessel it is negated. (5) Polyvalent general capacity that is not attached to a registered vessel for a period of more than 2 years expires.
2.4 Vessels targeting Shellfish The shellfish fleet is here defined as vessels under 13 m in length, as the vast majority of such vessels depend largely on shellfish. This cut off, however, is not reflective of any licencing or policy condition and many of these vessels also fish for other species. In addition, a number of vessels over 18 m target crab mainly in offshore waters (vivier vessels) and 14 vessels over 10 m in length were authorised to fish for scallops in 2020.
The number of vessels in the Shellfish fleet increased significantly in 2006-2007 as a result of the ‘Potting Licence Scheme’ which regularised many vessels that were operating outside of the registered fleet prior to 2006. The polyvalent potting segment was established at this time. The number of vessels in this segment is declining year on year due to de-registration and movement of vessel owners into the polyvalent general segment. There were 329 such vessels in 2020 compared to 490 in 2007. The number of vessels in the polyvalent general segment
6
S LL S L
inc e e e on e et een n t ec ine e on e om e e ig e
le ength nd it r ile the rish shell ish leet l lent ll l lent tting ll essels in s e i i seg ent ll lt re essels essels er ishing r r nd s ll re n t in l ded e r lt re l lent ener l l lent tting e i i t l er essels er ge ength er ge s
S LL S L
er ge s
le nn l h nge nd er ent ge h nge in the n ers essels er leet seg ent in the nder hell ish leet e rs lt re l lent ener l l lent tting e i i t l h nge in n er essels h nge in n er essels
S LL S L
er er essels
m m m m m essel si e teg r Fig re nn l trends in the n er registered se ishing essels length teg r
L S
Shellfish Landings 2004-2020 nn n ing o c t ce n n i e e c ing n i e m e ee hich i e i o on g o ing ing the e io ie om high o tonne in to o o in L n ing e e t n e tonne in e
n m e o ecie ch o te n ti e o te n h im e t gete e e n e m in ength the e e e o not e o t n ing c t ing the e t i i ic t e to the ge n m e o e e n the m i con ignment in o e P io to the e t e e c t e the S P th o gh in o m tion g the ing om e n o t ing t co ecte n e the e n e e o i t e i h eg tion hich o ige e to og the ch e o i h t the i t oint o e om i hing e e
L n ing t o ce t in ecie th t e ect to m n gement n coc e th t e m n ge oc o te o he e S P h e igiti e he i h egi t tion oc et n con ignment t to e o c m o i e ition t on n ing e te to og oo t o e note
he e t ic he o i n emic e to e i ic t n e t icte m et o i h o ct c o the o inc ing e n e o t to o e n i he e e e igni ic nt i e ence in n ing o n m e o ecie in com e to tho gh c n ing ec ine om the e the ec ine o tonne in com e to Sc o n he n ing e n tonne e ecti e in com e to he e n inc e e in coc e n ing o e e to highe in n in com e to
ot e o he i h n ing e c ing m e n in €53.4 million com e to €6 mi ion in
a le 4 s i a es f annual landings (tonnes) and value (€) of crustacean and i al e shellfish e l a ns and ssels in eland 2004-2020 s e L g de la a i ns and sales n es f essels nde 0 shellfish egis a i n d e s - da a ni al e e il is f sales n e da a he s es 2020 al e da a a aila le f a i e s e a i e f in
ea ing S all ing L s e e i in le hel Sh i s e a i e een s all el e a la S f a S ide a fish a la s Sh e a le al nnes di le a di le 2004 4 4 56 6 4 5 4 5 543 4 6 533 200 5 635 3 4 5 5 4 5 45 4 3 4 4 5 4 200 4 6 5 3 44 3 33 6 53 34 54 46 5 200 5 53 3 6 3 635 3 5 6 4 4 6 356 643 6 3 200 64 3 4 4 4 4 6 55 53 45 3 200 6 6 4 3 5 43 3 3 3 5 5 443 3 44 3 3 20 0 6 5 4 6 35 34 4 34 6 4 5 3 4 5 20 6 3 3 35 64 6 3 5 4 3 4 4 5 20 2 6 6 4 3 3 44 5 4 6 5 33 4 53 4 3 20 6 5 3 54 3 4 66 5 4 5 365 3 34 3 3 3 4 5 365 20 4 5 34 456 35 3 65 3 6 3 4 4 3 6 43 20 3 3 6 5 53 3 4 6 4 5 4 3 5 20 464 3 6 36 5 5 65 3 66 20 4 64 3 5 3 6 4 3 45 5 54 44 20 63 36 343 5 44 3 5 36 33 4 5 4 4 446 20 646 3 3 4 4 6 65 5 3 44 356 5 5 5 5 4 2020 5 335 6 4 3 5 56 33 3 3 35 3 64 54 6 6 ni al e 2020 €1.76 €10.54 €13.57 €2.49 €1.56 €15.30 €1.48 €1.93 €2.22 €0.51 €32.20 €5.00 €0.42 €2.3 al al e 2020 illi ns €9.389 €17.818 €5.737 €0.000 €8.671 €3.565 € €1.093 €0.602 €0.026 €0.182 €0.409 €3.205 €0.065 €2.660 €53.422
4 Lobster (Homarus gammarus) a ag m a o ster stoc s are anaged using a ini u landing si e ( ) of 87 a a i u landing si e ( a ) of 127 and a ro i ition on t e landing of v notc ed lo sters. e nu er of v notc ed lo sters released annuall as 5 000 11 000 individuals during 2002 2008 10 000 15 000 during 2010 2013 and 25 000 32 000 annuall during 2014 2018. e recent figures re resent a out 16 of fe ale lo sters landed. ro i atel 300 fis er en artici ate in t e rogra e.
n 2020 61 of t e re roductive otential in t e fe ale ortion of t e stoc consisted of legal lo sters et een 87 127 v notc ed lo sters et een 87 127 accounted for 12 17 as rotected t e and a furt er 9 as accounted for lo sters a ove t e a . ro i atel 33 ercent of t e lo sters a ove t e a ere also v notc ed. is dou le rotection is a legac of revious v notc ing rior to introduction of t e a . co ination of t e and a rotects 26 of current re roductive otential and v notc ing rotects a furt er 12 .
o inal stoc status indicators landings er unit effort discards er unit of effort and v notc ed lo sters er unit of effort s o ed sta le or ositive trends during t e eriod 2013 2019 in ost coastal areas. e inde of undersi ed lo sters increased fro 2015 2017 and as sta le in 2017 2019.
onservation easures s ould e aintained. e a is a si e refuge for lo sters t at ave reviousl een v notc ed. notc ing s ould target lo sters over 95 to a i ise egg roduction rior to re air of t e v notc and s ould e directed to coastal areas ere t e revalence of v notc ed lo sters is currentl lo . ecific targets s ould e set for t e ro ortion of t e ature fe ale lo ster stoc to v notc and ac ieve ent of t is figure s ould e onitored t roug log oo and o server rogra es.
eliance on t e v notc rogra e ic is ased on voluntar artici ation to rotect s ould e reduced and re laced it ot er easures if t ere is an decline in u ta e of t e rogra e. ta e s ould e revie ed annuall .
ssu s r a o ass ssm o o s r s r 600 . .
. . . .
. . .
.
12
. . .
. . .
a ag m u s . 2006 . . .
a ag m m asur s . 87 . 127 2015 . . . .
o r u o o o s r a o m asur s o r ro u o a e e t t o o t e ot e ro r e 2002 2008 5 000 11 000 . 10 000 15 000 2010 2013. 2014 2018 25 000 32 000 2 .
12 . 2014 2017 2018 3 .
1 2004 2006 8 2018. 1 1 100 16 4 .
200 2010 2012 300 2014 2016. 600 . 100 200 2002 2013 40 60 2015 700 900 5 .
13
35 000 30 000
25 000
20 000
15 000
10 000
5 000
0 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
re ot ber e t o ot e obsters re e ses
30 000 25 000 20 000 15 000
10 000
5 000
0 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
re ot ber o obsters re e se ross o t es
14
87 9 8 7 6 5
4
3 2 1 0
re er e t e o obsters o er ot e
2002 2019 1000 . . . 800
600
400
200
0 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
re ber o orts s bo ts ot re e se e e ts
e t o s bet ee bers re e se bers t se . .
2016 2019 2015. 6 . .
. 6 7 . .
15
re o t e ot e obsters er t o e ort ( ots) ( ) or t e e t e esse bser er t or o t es e e r s o e s t t e r st r e t o ( e or e or bser er ro r ) e r rters re s e re te
re ot e obsters er t o e ort ( ots) r t e obser er t st t e t e ber o obster re e ses
16
ro u o a . . . ’ 127 .
60 70 87 127 2009 2020 8 . . 2020 61 87 127 12 87 127 17 9 . 33 . 26 12 . 9 .
re t e str b t o o re ro t e ote t ( ) ross s e sses o ot e o ot e obsters re o s o b e o r e r e st t te bser er t
17
re r o t e str b t o o t e re ro t e ote t obster sto s o ser e b ot s e s e e s res or ) re o s o b e b) ross re o s o r e r e st t te bser er t
a ra s e so tre s
L
re e s (to L ) ers e s r s (botto ) o obster er t o e ort ( ots) or t e ( ) bser er ro r e ( )
Crayfish (Palinurus elephas) ana e en a i e r s re e s s e ( L ) o ere re t o re s o e o est se o r ee ose to ett ot e r s ot be e s e s re s tro e to rote t t e r s rre t s er te o ser t o e s t ere s o ot s e e s s
ber o e ere rote te s e es re t s b t r e es t e ets se to t r et r s e s er o t e so t est o st rt r o er s t re o ers t o e s obr s s ose to re se o ts re s es te or rbo r or o se er r b bro r b r s obster re t e ost o o s e es t e t e e s e es o e s obr s (s tes r s) o r t e b t te s te e s r er s te b e ( o o ) s te re r t e ere
t es o r s r ro s er t e o et e s r es se so eo r bo t o t e t s er t e L b t t s s er r b e ross e rs
t s o s so e o e t t r t o bet ee r s sto s o ort er r e t e est o re o e er t e r s re e se o err e bee re e te re t re ose to re e se o t o s o er ber o e rs t res e r s o st ters
r t e ere s e es ot s st b t ort t se b t e t e et s er e s res s o be tro e to e te t e b t o r t e ere s e es to s t re e t e b t o rote te s e es ssues rele an he assess en he ra ish isher
ana e en uni s
ana e en easures
a h p si i n
a i s a h si i i a s ar i rayfish ff h s h s as f r a a a ar a rs a h i a h y ar y a a s i h sa i r ra i s a i r Cra ( a a ra h a la) r Cra ( an er pa urus) Crayfish (Palinurus elephas) s r ( arus a arus) a (P lla hius p lla hius) r ( ph hal us a i us) fish ( phius spp) a a (P lla hius irens) r ( ualus a an hias) h r a ( a a la a a) r y a ( ali h erus r pus) i ifi a fish ( li rhinus spp) ay ( a a n a ui) ay ( a a ra h ura) a r a ( ip urus in er e ius) ai ay ( a a i r ella a) har ( ua ina s ua ina) C a ( isp urus a is) i ay ( as a is pas ina a) C ay ( eu ra a nae us) hi a a ay ( a a un ula a) a
a h ra es
i r Ca h ra ( rs ) f rayfish ff h s h s as f r a
i r is ri i f a h ra ( rs ) f rayfish i
i r i is ri i f rayfish i h a h ff h s h s as r r a
a re ap ure a a
i r as r a r a a f r rayfish i ra i f rayfish a ff ri a y i (s r ar ia a r s ) a r a r ff rry a ay i f rayfish i r a i i si a i ff h rry as C i r a r a a i r a i i si a i i r h rry n re s rai h lines erlan h a ri y f r a r s ar s r as si s y ars si a i r r i f a r a r i ias ha si
Brown crab (Cancer pagurus) anage en a ce h ra fish ry is a a y a i i a i si f h r ar ay i i s ss s r i h i i a y s si i ar a hi h i s as s fr r h ay s h a as a rf r a ss s r i C ar a
h ra fish ry is i r si a a fr r ia ss s a a s i ifi s r r r ra a i i si is ri i a a f h a i s is a r ss rs s i air a a r s i a h s a fishi ff r h ia i i y f fishi a rr r i s f fish r f h s a s f h s r i a h s a a r i i h si i ar s a sh s ai i a
i ri a a a a s a ar is i f s a a ri fr h s a a sh a s y ar y ar i i h a i s r i ff r a is ar s r i ff r si i h fish ry ff ay a a h s r s ar a s ra y s r i h r as a ar as h h h f si ifi a y r s h s fr r r i rfishi h a a ar y si a s a i i s a a a a i y i i r r i i r y ars i ha r s i is ar ra s ( f s a r ra ) ar a s a i
h r s s r i h a fish ry a a ar ir y sis i h s i air a a hi h i rsa y si a s a si ifi a i i h rf r a f h fish ry i r y ars Ca h ra s ha i ar ri s ha i a fishi ff r r ss (a ass ia s s) has i r as h ia i i y f fishi is r
i i a a a as r s sh i r s r s a i s hi r r i r ai s h r is a i s a r i s i air a a f r a i i a as r s r f rr i s i a hy s s as a s si ra as h ai a r s a hi h r a i y ra r i r a a a a a h h r is a si ifi a ris f ra sf r f fishi ff r i h r as a s r fish ry if ra a h s i i
ssues re e an e assess en e cra s er
anage en un s
r oc a n n or Brown crab
anage en easures e s r u n n ca rs
r r b on ( b n ) o crab ro ob r r ro ra b w n r n a n ow ( ) an ( ) n an n o ca o a ar
Ca c ra es
nn a r n
r nn a an an ( o ) or b r r an ro ra a a ro r bo ar n brown crab an w r brown crab ca a b ca c
r nn a an an ( o ) b oc ar a or r ar n crab an a o w r crab ca a b ca c r n
a ona r n
r on an ( o ) w an ar a on or r w r crab wa ar (b ) an ca r a b ca c (brown) or on a n n ac ar ow ann a an ar ar r a n r an w
e a n c an n
r an n ( onn ) o brown crab (Cancer pagurus) n on a an b ( a n oc ) b r o rc o boo a a or abo an a no a a or n r
n o effects are Generalised Linear Models (GLM’s) and ’s
~ ”cs”) + s(Vessel ~ ”iid”)
𝜂𝜂𝑖𝑖 = 𝑙𝑙𝑙𝑙𝑙𝑙(µ𝑖𝑖) 𝛽𝛽𝑜𝑜 𝛽𝛽𝑌𝑌 Landings𝑖𝑖 ~ 𝐺𝐺𝐺𝐺𝐺𝐺𝐺𝐺𝐺𝐺 (µ𝑖𝑖, 𝜙𝜙 ) 2 𝑣𝑣𝑣𝑣𝑣𝑣[Landings𝑖𝑖] = µ𝑖𝑖 /𝜙𝜙
𝜙𝜙 = exp(𝜃𝜃 ) predictor η ϕ is the precision parameter from the gamma distribution and β (“cs”) and a single random effect (“iid”) for Vessel ID, to account for potential co me vessels. The “offset()” is used to incorporate the fishing effort (Number
N
r an ar n o crab ab n anc ro ro ra a r a n wo r n o or a on ( a ar a c oo ar a n ) a r on n ca a ro a con nc n r a nn a an raw (b ac ar ) a or co ar on
n r r a on o ca c ra a a The ear on ear decline in the observed and standardised L inde bet een and has not been previousl observed in the time series hich e tends bac to . lthough this inde can be confounded b changes in grading practice, unrelated to the minimum landing si e, it is unli el to be the cause of the decline in this instance. bserved discard rates (D ) also declined from in parallel ith the L inde . Decline in L could be lin ed to gro th overfishing hereb the removal of crabs above the ML occurs at a higher rate than the can be replaced b gro th but corresponding declines in D and L signal an overall ear on ear reduction in the abundance of crab in the fished area. rabs in the discards are not all recent recruits to the stoc and include a number of age classes. The decline in discards, therefore, ma signal a reduction in recruitment in the past number of ears.
The minimum si e of mm and more recentl mm has been regarded as sufficient to protect the stoc from recruitment overfishing given that the si e at maturit is appro imatel mm. pa ning escapement is, therefore, significant, if it is above of hat it ould be in an unfished stoc , and a number of spa ning events occur before crabs are e posed to fishing mortalit . igh grading at observed modal si e of about mm provides further protection. ishing is unli el to be the sole cause of the recent declines in stoc abundance. o ever, recruitment decline combined ith high fishing effort ill further reduce spa ning stoc biomass. In such a case, fishing mortalit should be reduced to avoid driving the stoc to even lo er levels.
o on o r nc In the earl s vessels fished from the Inisho en peninsula. this had increased to vessels each fishing appro imatel pots. rom there as a gradual decline in the number of vessels and b ust remained. The relativel small area fished b the Malin ead fleet disguises it’s importance as a ma or producer of crab at over , tonnes per annum in . mplo ment on vessels in as per boat and up to fishermen. In vessel cre si e as representing a ma imum of fishermen. In an estimated vessels fished crab in Donegal and a further fished out of north Ma o giving a total of vessels. The total number of vessels targeting
r b r o an o n crab r n an ( r nar )
r r b on o n ac n on a n an n a an on a n ( ro a B r r o rc r )
r r b on o n ac b a o an on a n r ar n crab n a a or a a n b r o o nor w on a ar n wo r n r w o co an an nor o o r own a a or o r ar no own b r b c o r on
onna r a a on r n an a
n
fishermen’s primary fishery is crab there is a
. Of 13 respondents 9 answered ‘No’. Only 1 respondent said ‘Y ’
r ca n cono c c n on a crab r ro onna r a a co c n r c n n con on n
O N
o on n ost fishermen respondin to the estionnaire proposed a closed season to resol e the iss es identified in the fishery. i e proposed to close between an and ne or for a n mber of months in the first half of the year. wo proposed to close from No ember to the followin sprin . Other sol tions proposed incl ded introd ction of a total allowable catch an increase in the minim m si e or to enforce landin of hi h ality crab only hi h radin and landin lower ol me .
r o on n o cono c c n on a crab r ro onna r a a co c n r c n n con on n
3
O
Razor clam (Ensis siliqua) ana n a i co rc a o ra or c a oc n r an ar a b r w c ro a o b o a b or ra a o n nor an o r a r or a a a r ca r on w coa a o ra cc n r o n ar ana n an n r c n ar
an n n or r a c n b w n n b r o n r ncr a ro n o n an an c n o n n ca or ( a an n r ca c r o r) ow n can an r n c n o b w r ab ro a o b o a r o ow n a r w o a a an ar a on ro oco ar ro a ro a onn n o b w n onn n o a on ra wa abo r ann ar c a w r b w n an b w r ab or ncr a b w n on corr c a ra ca c ( ) a n or or r a n ca a an n a occ rr n r o ar no a nab an a an n o b ca a onn rna o on ar onn w c a ra an n or r o r n w c r b o a a w r ab or o a a ra o a on ra o c o o w n b o a wa ab o b o a or a an n o onn
o r a r o n n an an c o nn a an n c n ro ron r cr n n n o ar Ba n ( robab ) wa ob r n r an b o a ncr a n can b w n an r ro o onn r r onn occ r n rrac o b o onn an o a on ra r co n on ba a o a on ra o ab b o a n nor r a b w n
an ra or c a r or o n a r occ r w n or c o o a ra con r a on ob c or c an ab a n ar a ar n ra n o a or c a r ana n a c n nor r a o b a a na ca a b ca c n n a Ba a a ana n a r n n a Ba o b n ro c o nab r co r o c an o on or c an n ar n co n o ow n r o a o n r r
ssu s l an ass ss n a la is a or clams occ r alon the east coast of reland in m d and m ddy sand sediments from ndal to blin and from ahore to osslare and in n mero s areas alon the west coast. second species is ab ndant in well sorted sands on the west coast. oth species may occ r in the same area. he distrib tion is c rrently nown from the data for the commercial fishery which operates in water depths of 1 m and from s r eys where there are no fisheries. ishin depth is limited beca se of the fishin method which ses hydra lically press rised water to fl idise sediments in front of the dred e. he distrib tion of ra or clams may e tend to deeper water o tside of the ran e of the fishery as the species occ rs at depths of p to m. owe er there is no e idence that si nificant biomass occ rs o tside of those areas already fished.
he efficiency of the hydra lic dred e sed in ra or clam fisheries has been meas red at 9 . he dred e therefore is ery efficient at remo in or anisms in the dred e trac . his is in contrast to
3
O
non hydra lic dred es sed in other bi al e fisheries s ch as scallop and oyster where dred e efficiency may be in the re ion of 1 3 . iscard mortality rates are n nown b t may be si nificant i en that dama e can be obser ed on the shell of discarded fish and nobser ed shell dama e may occ r at the dred e head.
is slow rowin reaches a ma im m shell len th of appro imately mm and has relati ely low prod cti ity. he apparent resilience to date of the species in areas s b ect to persistent fishin by hi hly efficient ears may possibly be e plained by immi ration of enile and ad lt ra or clams from areas o tside of the fishery. ome e idence of si e stratification by depth has been shown in ales and i en the nown mobility of the species s ests that post settlement mo ement and recr itment into fished areas may occ r. is faster rowin occ rs in hi her densities and reaches a smaller ma im m si e than .
cosystem effects of the fishery on the seafloor and on seabirds which feed on benthic bi al es is considered in the assessment ad ice.
ana n uni s toc str ct re is n nown. ar al dispersal and mo ement of eniles and possibly ad lts s est that the stoc str ct re is relati ely open alon the east coast of the north rish ea and that indi id al beds are nli ely to be self recr itin . ishin is contin o s from north ndal ay to alahide. toc s in the so th rish ea are li ely to be separate to that north of blin i en the different hydrodynamic and tidal re imes in the two areas.
Other isolated stoc s occ r in many locations on the so th west and north west coasts. isheries occ r in lifden ay nis ea slands in ayo allina ill ay and aterford est ary.
ana n asu s New mana ement meas res were introd ced for the osslare – rracloe fishery in ecember 1 . hese incl de an increase in from 1 mm to 13 mm fishin ho rs from to 19 . tonne ota per essel per wee c rrently 1 dred e per essel not to e ceed 1 cm width with bar spacin not less than 1 mm prior notice of intention to fish and ad ance notice of landin mandatory s bmission of atherers doc et information on landin s date and location of fishin and a defined fishin area to minimise o erlap with Nat ra sites. he osslare ay fishery was closed by ol ntary a reement in 1 and 1 d e to rowth o erfishin .
n the north rish ea the wee ly essel is s from an ary 1st 1 with a prohibition on landin on ndays 1 . he fishery is closed by ol ntary a reement in ne d rin the spawnin season. he minim m landin si e increased to 1 mm in 1 .
isheries on the west coast ha e ol ntary arran ements in place based on s r ey biomass estimates and an a reed har est rate.
ll essels fishin for a or clams m st ha e a f nctionin i system on board and report position at defined fre encies. Only 1 class of prod ction area can be fished d rin a fishin trip 1 .
3
is a of approx. €6.5m in 2015. The catch is exported mainly to the Far East. Unit prices vary by grade or shell size from €4 9 per kg. The fishery, relative to other shellfish, could be classed as ‘medium price and medium volume’.
r r o o or l or razor clam or r a r a
a
r al la o Ensis siliqua or r a ( ) o rc rom lo oo ll a r r a a a al o
There as a consistent relationship bet een i activity and landings during 2016 2020. Effort and landings accumulate through the year other than une hen the fishery is closed. effort declined generally during the period 2016 to 2020 and landings declined from 201 Figure 29 .
r R la o mo l or ( r ) a la or r a razor clam r
9
r survey encompassing all of the areas hich are commercially fished for azor clams as completed in the in une 2020. The survey follo s the design in 201 2019 hich used an i grid to allocate survey effort i activity is seen as a proxy for the abundance of razor clams. The survey domain, hich extended from north undalk ay south to alahide and ambay, as divided into 5 areas ith approximately 160 stations in each area allocated to each of 5 survey vessels. ithin each area, 4 i effort strata of the same surface area here defined, and 50 stations ere randomly assigned ithin each strata, to ensure an even distribution of randomly assigned grid cells across the range of i effort. The survey as mostly completed over a 4 5 day period, depending on area and vessel.
iomass at each station as estimated as the product of density number of individuals caught per meter s uared to ed area and mean individual eight calculated from the size distribution at the station and a eight length relationship. iomass as then interpolated over a 100 m x 100 m grid using ordinary kriging on log biomass . Total biomass as then estimated as the sum of mean estimated biomass, using a geostatistical kriging model, raised to the surface area of the cells. inety five percent confidence intervals ere estimated based upon 250 random realisations of the modelled biomass using conditional aussian simulations. This method preserves the spatial structure in the biomass, as described by variograms, hich modelled the spatial autocorrelation and spatial structure in the survey data.
standardised protocol as established and applied to the survey data from 201 2020 in order to avoid potential differences in biomass estimates from year to year due to the change in the total surveyed area, the geostatistical assessments modelling routines and to control for various issues surrounding the ac uisition of accurate data during surveys. n this report these protocols have been applied retrospectively and biomass estimates may therefore be different to those reported in previous years
oma iomass varied from approximately 10,000 tonnes in 201 to bet een 6,000 ,000 tonnes in 201 2020 Figure 0, Figure 1 . ver 90 of the biomass is above the minimum landing size of 1 0 mm.
40
r r oc oma o razor clam or r a o o al oma o om oma r a r a ll l mm
41
r r o o oma o razor clam or r a r (a ) o cal r c acro ar
42
z r o The dominant modal shell size in 201 as 1 0 mm ith a second mode at 1 0 mm. n 201 the modal size as approximately 145 150 mm as a result of annual gro th of the main cohort present in 201 Figure 2 . The mode at 1 0 mm present in 201 as absent in 201 indicating that clams over approximately 1 0 mm ere depleted bet een 201 and 201 . There as no evidence of significant recruitment into the stock in 201 or 2019 and changes in size and biomass in those years are due to gro th and mortality. ecruitment as observed in 2020 and there as an increase in the modal size of commercial clams from 150 mm in 2019 to 160 mm in 2020.
r z r o o razor clam or r a rom r a a
l o corr c a ra ca c a m ( ) assessment estimates the sustainable catch by penalizing the average yearly landings based on the observed depletion in abundances indices. f there is no depletion the sustainable catch is simply the average of the historic catch. The base formula only gives a single estimate, ith no confidence interval. ayesian implementation of the model, using life history based methods to estimate the msy o and Fmsy ratios, as developed to take into account most of the kno n sources of uncertainty and to provide a confidence interval for the sustainable catch. The model as fitted to landing per unit effort UEs estimated from logbooks and diaries from 2001 2005 and 2009 2016, as ell as UEs for the ormansto n bed extracted from Fahy and affney 2001 for reference as they estimated 60 depletion in uly 1999 . ny changes in high grading at sea ill affect the estimate.
The assessment suggests that the sustainable yield for azor clams in the orth rish ea is 60 tonnes, ith a 95 confidence interval of 01 to 409 tonnes Figure .
4
r a a mo l a arl r a a ocorr la o R( ) mo ( l m a a ) al r a o ma l a o mo l ar o r
oc oma ca or tock biomass indicators UE kgs.day 1, UE kgs.hr 1 ere estimated from data from shellfish registration dockets in 201 2019 and from data in 2011 2019. The indicators may be increasingly biased in recent years due to high grading at sea given that the market price increases significantly ith size grade and kippers ill try and maximise the value of the eekly uota of 600 kgs. These data are available for a longer time series than the actual survey biomass estimates.
atch per vessel per day Figure 4 in the data declined from approximately 00 kgs in 201 , to ust under 200 kgs in the period of 201 2019. The data sho s a similar decreasing trend, ith a slight increase in 2019 to approximately 250 kgs. atches per hour in the data declined from 20 kg hr at the beginning of the time series to 12.5 kg hr by 201 2019 Figure 5 .
r ra (a a ar a o ) o ca c r l r a o Ensis siliqua or r a rom l l l ( ) a ll R ra o oc ( R ) rom
44
r al ca c ( ) r o r a a rom a a
a c a c verage catch and of biomass landed in the period 201 2020 as 46 tonnes and 6.9 , respectively. urveys indicated that biomass as stable during that period and there as some evidence of increase in modal shell size and grade structure bet een 201 2020. UE varied from 1 4 20 kgs per day data Table 6 . These average landings, during a period of stable biomass and UE, is consistent ith the estimate of sustainable yield of 60 tonnes. andings in the period 2015 201 averaged 9 tonnes and biomass declined in 201 and UE declined from 20 to 1 kgs per day.
anding options for 2021 are therefore
- pply the estimate of 60 tonnes - pply the 201 2020 average landings of 46 tonnes - pply the 201 2020 average exploitation rate of 6. to 2020 biomass estimate for a landing of 515 tonnes
a l r la oma o oma a la r a r c ar r la o a a l o a ma ar a oma lo a o ( a ) 69 290 41 26 1,100 220 204 14 10,000 .14 1 6 16 6,000 11.9 1 4 4 ,000 4.6 191 00 ,500 4.00 20 a ra ma o a a l la
45
co om c ca or ndicators of economic viability of fishing are derived from data that includes partial costs namely fuel. et value per hour at sea increased from 2011 2015 due to significant price increases for razor clams and also reductions in fuel price even hen catch rates ere declining. alue per hour at sea peaked in 2015 and 2016 and then declined due to continued fall in catch rates, increase in hours at sea and increases in fuel price Figure 6, Table . rice increases in 2019 increased profitability relative to 201 and 201 .
r al ( a al m l co ) r o r a a Razor lam or r a r rom a a
a l al r l co r a a r c o clam a (o l) al o ca c a r a a l l l r r c o r al o al ar a r co r clam r r a a a l la r r a a a €208 €0.65 1 .2 €2.21 €599.00 €243 €0.80 1 .1 €2.54 20.40 €638.00 €36.90 €272 €0.92 14.2 €3.45 20.20 €669.00 €45.60 €226 €0.88 14. €3.79 19.0 €702.00 €45.70 €180 €0. 9 12.9 €4.60 1 . 1 €908.00 €65.00 €148 €0.73 12.6 €5.60 1 .90 €1,185.00 €88.00 €136 €0.60 1 .4 €6.20 15.40 €1,077.00 €85.00 €214 €0.62 19.2 €5.90 11. 0 €1,087.00 €59.00 €197 €0.63 16 €5.78 1 .00 €1,063.00 €62.00 €302 €0.76 19.9 €7.49 12.20 €1,553.00 €74.00
co m c o r The fishery may impact a number of ecosystem components in the including seafloor faunal communities and sediments and also some seabirds that rely on bivalves for food and hich are sensitive to disturbance by marine traffic.
46
R c mo or o a al rro al 2017 2020 ), the locally called ‘blood razor’ ( . . 37 . 2020 .
. 2017 2020 38 .
r a c o om a c o al r cor r Razor clam (Ensis) r o al m r r cor o ac a al r a ar o r or o o r cal o a
47
otal recorded r ey
r a c o om a c o al r cor r Razor clam (Ensis) r al a o al m r r cor o ac a al r a ar o r or o
here a ote t al or d t rba ce a d d lace e t o o o coter ro the r eed ro d hallo coa tal ater o the orth r h ea d e to the re e ce o h e el o e er, there o e de ce that th d t rba ce act ally d lac o o coter
o o coter ora e o r c al b al e a o o ed to dee b rro b al e the area here ore, a y cha e tr ct re a d ct o o the hab tat re lt ro the razor cla hery ll act o the ora o o o coter er al d tal eab rd data ho h h ber o o o coter occ r alo the or a to coa t a d o ter dal ay area here the razor hery occ r
u is a a he hery the o th r h ea o e ed a d crea ed ro to e to to e bet ee a d o er to e ( re ) a d decl ed to bet ee to e (lo boo a d ale data) he e decl e corre o ded th a red ct o h e ort the o lare ed art c lar a b o a o lar e rade cla had decl ed the er od to a d there a ol tary clo re (or art clo re) the er od to e able ro th o a tro year cla ar et ere l ted he ater ord e t ary hery a clo ed by co rt order
r a ( o ) o razor clam o r a cla ro c o ar a ( ) o rc o oo al o a or o la
or he a or ty o e ort occ rred o lare ay a d ( re ) altho h the la d data are h her or rracloe here are o data or or e ther area Annual landings in these years was about 70 tonnes and there was a voluntary ‘closure’ in place by a ree e t o lare ay o e o the e ort tched to ater ord e t ary a d early
r r o o or ( r ) rraclo a Ro lar a or a
A A
r a a toc s o a or cla s in the outh rish ea are distributed in two ain beds osslare and urracloe ith the e ception o the southern li it o the urracloe ed the distribution o ra or cla s is well nown and the e tent o the beds is included in both surveys
Ro lar a n osslare higher densities o ra or cla s occur in the core o the survey area igure and si ilar spatial patterns are ound a ong all si e classes A strong recruit ent event was reported by the ippers in 0 igure shows the growth pattern o this cohort or the period 0 7 0 0 his growth accounts or the linear increase in bio ass ro 000 tonnes to 00 tonnes during 0 7 0 0 igure About o the bio ass is above the 0
a) )
c) )
r r o o Ensis siliqua or all z cla Ro lar a a b c a d o r cal acro ar
0
A A
r z r o o razor clam (Ensis siliqua) Ro lar a r a b c a d a a ar a ar o am l or r ar l o a al r o
r ma o oma o razor clam (Ensis siliqua) Ro lar a or all z cla ( o ) a z mm ( o om)
rraclo At urraloe the highest bio ass o ra ors is ound in the southern li it o the survey area igure igure shows a clear shi t in the si e distribution ro 0 to 0 0 due to annual growth and a ode at appro i ately 0 his inter annual growth e plains the increase in bio ass shown in igure io ass was appro i ately 000 tonnes in this area in 0 0
A A
r r o o Ensis siliqua or all z cla rraclo l ) a r ) o r cal acro ar
r z r o o razor clam (Ensis siliqua) or r or a a a ar a ar o am l or r ar l o a al r o
A A
r ma o oma o razor clam (Ensis siliqua) rraclo com or all z cla top a mm botto a c a c urvey esti ates o ra or cla bio ass between 0 7 to 0 0 continue to show signi icant increase in bio ass ainly due to growth o a year class that recruited to osslare ay probably in 0
io ass in 0 0 was appro i ately 00 tonnes ver 0 o this was in osslare ay andings overall should not e ceed 0 tonnes in 0 applying e ploitation rate as in option above or the orth rish ea ot ore than 0 o this tonnes should co e ro the urracloe ra or bed
Cockle (Cerastoderma edule) a a eme t ad e al a coc l r ma a r a a ra r a ra (ma a m ) la o occ r a oma l a o r clo ( o oma o r o ) a o o m r or a ra ca c r oa r a cl lo mm ll o a o o r l r a or rm ol r orc
oc a a al r a a o a a r o r co m ca or ( c a a r o la o ) ar ra o ma a m a c r o r la o a r al a a a mar comm r a l lo rm ( ) a ra m r o r a ra rom o cl r r o r r r r a corr la o o r oma o coc l a m r o o rca c r a ollo r
r r r ma o coc l oma a o a co oma c r a a ollo rom a ro r cr m a la or a o
ar co rol r l c a lac c o l co l m r r c oma a c a r o o l cr a o a l a o ca o o r corr la o o r coc l oma a o rca c r m r ma o o o r coc l oma o l m ro
a a c o a o ra l co r a o a o r al a a c coc l r occ r a r mar ma a m o c or r o r c r o r r cr m a l r a o r a co r a o o c or a a a a c ar ro c coc l r or o l c o ma a m la co r r o al c o a a a a r
ssues rele a t to t e assessme t o t e o le s er here are a nu ber o coc le beds around the rish coast however in recent years the ain ishery has occurred in undal ay
ecruit ent o coc les in undal ay occurs regularly but overwinter survival in particular is highly variable As a conse uence bio ass in so e years is insu icient to support a ishery n ost areas growth rates are lower than in undal and coc les need to survive over winters to reach co ercial si e co pared to winter in undal
Annual surveys provided they are co pleted close to the prospective opening date or the ishery provide good esti ates o bio ass available to the ishery and the prospective catch rates rowth and ortality result in signi icant changes in bio ass over short periods o ti e e erence points or sustainable outta es are un nown n the case o undal the harvest rules see to have stabilised stoc bio ass and aintained productivity
undal ay is under a atura 000 site anage ent regi e and a ishery atura plan or coc les oc le is both a characterising species o designated habitats within these sites and also an i portant
ood source or overwintering birds anage ent o coc le isheries ta es into account the conservation ob ectives or these habitats and species
ontinuing co ercial isheries or coc les in atura 000 sites will depend on avourable conservation status o designated environ ental eatures that ay be a ected by this ishing activity or a clear de onstration that changes to designated eatures are not due to coc le ishing
a a eme t u ts oc le stoc s occur in intertidal sand and ud habitats hese habitats occur as isolated and discrete areas around the coast and as a conse uence coc le stoc s are probably local sel recruiting populations
Although there are any coc le populations around the coast only undal ay has supported co ercial dredge isheries in recent years here is a s all scale co ercial hand gathering ishery in astle aine arbour erry and in ru cli e ay ligo o ercial stoc s also occur in ra ore ay and oodstown o ater ord and in lew ay o ayo but these stoc s have not been co ercially ished in recent years n addition coc le stoc s occur in ayo other than lew ay erry ligo and onegal in particular but these have not been surveyed and are not co ercially ished
a a eme t measures he anage ent easures or the undal ishery are described in year ishery atura plans s 0 0 and 0 0 0 and speci ied in annual legislation in the or o atura eclarations www ishingnet ie hese plans were sub ect to screening and appropriate assess ent as re uired by the abitats irective Article and the irds and abitats egulations 0 o 0 A new ive year plan will be proposed by industry or the period 0 0 he per or ance o the previous plans in ter s o protecting coc le stoc s benthic habitats and bird populations were reviewed in 0 0
n undal ay a coc le per it is re uired to ish or coc les either by vessel or by hand gathering he nu ber o vessel per its is li ited to or erly
Annual A is set at o bio ass esti ated ro a id su er survey he ishery closes i the average catch per boat per day declines to 0 g even i the A is not ta en his provides additional precaution given uncertainty in the survey esti ates pening and closing dates are speci ied annually he latest closing date o ove ber st is i ple ented even i the A has not been ta en or i the catch rate re ains above the li it or closure essels can ish between the hours o 0 00 and 00 a i u landing per vessel per day is tonne redge width should not e ceed 0 7 in the case o suction dredges and 0 or non suction dredges he national ini u legal landing si e is 7 but operationally and by agree ent o the licence holders the ini u si e landed in undal ay is his is i ple ented by using bar spacing on dru graders on board the vessels
nviron ental per or ance indicators are reviewed annually as part o the anage ent plans and the prospect o an annual ishery depends on annual evidence that there is no causal lin between coc le ishing and in particular the abundance o oystercatcher and other species o bird that eed on bivalves and the status o characterising bivalve species in intertidal habitats
u dal a o l io ass esti ates ro annual surveys in 007 0 0 are not strictly co parable because o di erences in the ti e o year in which surveys were underta en able he annual bio ass esti ates are sensitive to the ti ing o in year settle ent and seasonal ortality o established cohorts relative to the ti e in which the surveys are underta en evertheless since 00 surveys have been underta en either in ay une or uly
io ass has varied ro a low o tonnes in 0 0 to 7 0 tonnes in 0 io ass increased annually between 0 and 0 7 ro 7 tonnes to tonnes and was between 0 7 0 tonnes in 0 0 0 o ishery has occurred when the bio ass was less than 0 tonnes 0 n years when the ishery is opened the A upta e has varied ro 00 to 00 0 7 0 0 his depends on distribution o bio ass and the co ercial viability o ishing and ar et prices he A was lower than allowed or in the ishery plan in 0 0 by agree ent with industry
le l o C l o cockle lk o ( o e ) ( o e ) e C e o e C ( o e ) e el e e arch 77 7 0 n nown August 0 0 0 0 une 7 7 0 0 ay 0 0 0 ay 0 0 ay 7 00 une 0 0 une 7 0 0 0 une 0 00 0 0 0 uly 7 7 0 0 une 77 77 0 une 7 7 0 uly 7 0 0 00 0 une 0 70 0
e o A pre ishery survey was co pleted in une 0 0 he survey area was 7 otal bio ass was 0 tonnes able based on a geostatistical odel io ass o coc les over was tonnes igure 7
le o o cockle lk e o ( o e ) e e o ll e 0 7 0 0 0 o ( o e ) 0 0 0 0 o ( o e ) 0 0 0 0 0 o ( o e ) 7 0
e o e (k ) o ll cockle (le ) co e c l cockle ( ell ) ( ) lk e
e o ec e o parison o the 0 0 0 data shows growth o the 0 0 cohort to a odal si e o appro i ately in 0 and to in 0 0 igure o signi icant recruit ent spat settle ent occurred in 0 or 0 0 although survival o the 0 cohort has been strong as indicated by the increase in bio ass and high landings in 0 0 0
7
e e o o cockle lk l e l
e e o o e lo o e n the years 0 0 0 in season depletion in catch rates were observed in 0 0 7 and 0 igure o depletion was observed in 0 or 0 0 where catches re ained close to the 000 g per day li it throughout the season he level o observed depletion is negatively correlated with pre ishery bio ass hen bio ass is high ishing ti e is reduced and the leet can ove to di erent areas to aintain catches hen bio ass is lower 00 00 tonnes in 0 0 the leet is less able to aintain catches he observed depletions or absence o depletion indicates that in no case was the harvest rule bro en depletions were he depletion rates also suggest that the pre ishery survey correctly esti ates the bio ass which is used to esti ate the A he survey esti ate in act is li ely to underesti ate the ishable bio ass at the start o the ishing season as there is a signi icant increase in coc le si e between the survey and opening o the ishery even i this is usually only wee s his could e plain the less than e pected depletion rates
e e o c e e e l e e el e o e eek o e c eek o e cockle e
e e o eco e e ec wo ive year ishery atura lans 0 0 and 0 0 0 or oc les in undal ay A and A have been i ple ented he ishery lans included restrictions and li its on outta es and in particular a re uire ent to onitor e ects on the environ ent and the ecological eatures or which the ay was designated under the abitats and irds irectives ata ro intertidal habitat and bird population onitoring since 007 is su arised below
e l he nu erically do inant species o bivalve in the intertidal habitat o undal ay are coc le and he altic cla is ore abundant on the upper shore coc les ainly occur along the id shore and is do inant ro the id to lower shore he distribution o all species overlap revious studies in undal ay shows that coc le dredging causes ortality o in particular as its shell is lighter co pared to the other two species owever its overall sensitivity to abrasion pressure is low given its short li e cycle and high recoverability is uch less e posed to the coc le ishery as it is distributed on the upper shore ounts o the casts o the polychaete wor have been recorded since 0
he distribution o these species is esti ated during annual su er surveys 007 0 0 oth and can occur in high densities able 0 igure 0 he average abundance o both bivalves was stable between 0 0 0 istribution aps show si ilar distributions across the ti e series igure
le e e ( ) o e l e ulus te u s a oma alt a e ol c e e o re ola mar a lo e e e e o o e l co l e e l e e cockle e e o o e l ulus te u s a oma alt a re ola mar a e co ( ) l e e e e e e e e e 7 7 7 0 7 0 7 7 0 0 70 7 0 0 0 0 0 00 7 07 7 0 0 0 77 0 0 0 7 0 0 7 0 7 7 77 7
he divide between the sur ace o ygenated and sub sur ace anaerobic sedi ent is nown as the redo potential discontinuity layer his divide appears as a grey layer o sedi ent above the blac deo ygenated sedi ent below edi ent obility and biological bioturbation caused by eeding o in aunal deposit eeders increases o ygen supply to sedi ents and thus a es the o ygenated sur ace layer o sedi ent deeper utrophication and increased biological o ygen de and in the sedi ent reduces o ygen availability and the layer can then occur very close to the sedi ent sur ace ilter eeding bivalves such as coc les occur above the or at least ust reach the aerobic layer when eeding he depth o the
was easured at each station during the su er surveys ro 0 to 0 0 able 0 t has been consistent at an average depth o about 0 c since 0
e e e e e o ulus te u s a oma alt a re ola mar a e l e e lk
0
e l o o ulus te u s ( o ) a oma alt a ( o o ) e e lk
verwintering birds in undal ay have been onitored since the id 0s by i e s rish etlands ird urvey ounts are ta en at ey roost locations at high tide Additional low tide counts have been underta en periodically by the ational par s and ildli e ervice and the arine nstitute
he highest nu bers o birds all species in undal ay were recorded in winter 00 00 igure he long ter 0 average is stable with a range between 0 000 and 000 birds ear on year declines during the period 0 0 were reversed in the period 0 0
ata or di erent eeding groups na ely ivalve eeders ish eeders eneralist eeders nvertebrate eeders and egetation eeders show variable patterns igure ivalve eeders declined in 0 and re ained on average at lower levels up to 0 co pared to earlier years his decline also occurred in the generalist group with the e ception o 0 7
e e e e o ll ec e o e e e o e e e e o o o lk
e e e e o ee o o e e e o e lk o o
here has been no change in the structure unction or distribution o intertidal habitats which support these bird populations in undal ay since 007 and no signi icant e ects o coc le ishing on habitats has been ound ird populations not relying on coc le as a ood source are unli ely to be i pacted by the ishery
e c c e ystercatcher eeds on coc les owever wor contracted in recent years by the arine nstitute in undal ay also shows that it eeds on other prey and in particular it eeds e tensively in grasslands bordering undal ay report average a i u counts o 7 birds in their re erence period to 00 i e s counts o over 000 oystercatchers in 00 and 00 007 were the highest counts in the years ti e series igure ecent year averages and longer ter 0 year averages were and 7 7 birds respectively A year on year decline occurred ro 00 0 to 0 u bers increased ro 0 to 0
he nu ber o oystercatcher at other east coast sites south o undal ay hold lower nu bers o birds than undal ay igure en year trends in oystercatcher are stable or negative at ost o these sites here is a s all upward trend in ublin ay he year on year variation in counts is uch higher in undal than in other sites he year population trend or oystercatcher in undal ay is in line with or better than the year population trend in other east coast sites without a coc le ishery suggesting that the ishery in undal ay is not adversely a ecting oystercatcher populations
he nu ber o oystercatchers overwintering in undal ay is positively correlated with the post ishery coc le bio ass igure his is the bio ass that is available in autu n when the ishery is closed he relationship is leveraged by the coc le bio ass and high oystercatcher count in 00 0 At a coc le bio ass between 000 000 tonnes oystercatcher nu bers are variable evertheless the ini u coc le bio ass to open the coc le ishery is 7 0 tonnes and the relationship between coc le bio ass and oystercatcher nu bers suggest this ay be too low and could reduce the capacity o the site to support oystercatchers A change in this harvest rule to a higher coc le bio ass be ore a ishery could open would be ore precautionary
e e e e o o e c c e ( aemato us ostrale us) o e e e e e e e o o o lk
000 undal ay anny stuary oyne stuary ogerstown stuary alahide stuary aldoyle ay ublin ay 0000
000
000
000 ea oystercatcher nu bers
000
0 00 0 0 0 0 0 0 0 0
e e e e o o e c c e ( aemato us ostrale us) o e e e e e e o o e e l e e lo e e co cl lk
e el o e ee o e c c e ( aemato us ostrale us) e ( e ) o e cockle o lk e e c e e e o ol ock (cockle) ec e (o e c c e ) c o ( ) ( e o e o e c e) ( ee e ) o e cockle o e e o ec o e o c l e
Oyster (Ostrea edulis) a a e e t ad i e e ock e e e l e c o e o e e l o e e e c e c (c c l ) ce
ock o e e ll lo ll e e ce e lee e e e e o e o e ec e e l ock e ece o e o e o e ock e cl l o o c c o e ( a alla a i as) a ia ec o oo e l o le co o o e le e lo ock c c o e l e o ll ece e o e e o e co e c l e
e e ll l o e o l o e e l o e l ce o o e e e e e l o eco e l o l e e elo e o e o e o e o c o ock o l cl e e o c o cl e o l o c c o e e ce o eco e o cl c l c clo e o e e e e o l ll o o o o o e e o e e e o llo o o e o o ock eco e e e
e e e l o co e o e e e e ec e e ec c co e o o ec e e ee e e o e e o e e e e e l l o ee o co e e co e o o ec e o o e o o c o e c c e ec e e o o co e e co e o o ec e
ssues rele a t t t e assess e t t e ster is er A nu ber o native oyster beds occur as separate stoc s in ays around the coast io ass is currently low co pared to historic levels in ost areas nner ralee ay and lew ay holds the a ority o the national bio ass o native oyster
ecruit ent is variable in ost areas although settle ent occurred in all areas recently surveyed arval production and settle ent is conditional on density o spawning stoc high su er te peratures and the availability o suitable settle ent substrate
he ishery is anaged pri arily by a ini u landing si e o 7 7 he ini u si e is generally reached at age ysters generally ature well below the
yster stoc s ace a nu ber o threats including in ection which deci ated stoc s in the 70s and is prevalent in a nu ber o beds today and in 0 7 was detected in the previously ree ill hiar in ay ative oyster is also co peting or habitat with naturalised aci ic oyster in so e areas such as ough willy oor substrate conditions or settling oysters ay be li iting recruit ent and low stoc density ay also be reducing reproductive output ncreases in reshwater in lows to estuaries in inner alway ay reduces the area o suitable oyster habitat
anage ent authority has been devolved to local co operatives through ishery orders issued in the late 0s and early 0s or through 0 year A uaculture licences Although
conditions such as aintaining oyster beds in good condition or having anage ent plans in place attach to these devolved arrange ents in ost cases anage ent ob ectives and anage ent easures are not su iciently developed n ough willy and the public bed in inner alway ay all anage ent authority rests with the overseeing govern ent depart ent rather than with local co operatives
Although anage ent ay be devolved through the ishery orders or a uaculture licences vessels ishing or oysters ust be registered on the sea ishing vessel register A and operators ust also hold a dredge licence which is issued by nland isheries reland
he oyster co operatives operate seasonal isheries and ay also li it the total catch he A s ay be arbitrary or based on the annual surveys
All the ain oyster beds in reland occur within atura 000 sites yster is a characterising species o sedi entary habitats o large shallow inlets and bays t can also be a ey habitat or ing species in conditions where recruit ent rates are high and where physical disturbance is low eagrass and aerl or other sensitive ree co unities are co only ound on oyster beds in alway ay ill hiar in ay ralee ay and lew ay redging ay da age these co unities anage ent o oyster isheries needs to consider the conservation ob ectives or this species and its associated habitats and co unities
Annual surveys provide bio ass indices or absolute bio ass esti ates and si e structure o oyster stoc s annually oor in or ation on growth rate which varies across stoc s li its the assess ent o ortality rates and yield predictions
hese issues were discussed at the ative yster or shop in ctober 0 7 hosted by uan eo in larinbridge www cuanbeo co A new oru the rish ative yster isheries oru was established in 0 representing all oyster co ops to discuss site speci ic issues and uture anage ent and restoration o oyster stoc s A pro ect supported by the uropean onetary isheries und iodiversity che e on restoration o native oyster has been co ordinated by the since 0 7 and is wor ing with uan eo and a nu ber o oyster co ops hese pro ects are lin ed to the reland native oyster restoration networ https nativeoysternetwor org
a a e e t u its yster stoc s occur as discrete stoc units in a nu ber o ays around the coast Although native oysters were historically widespread in any areas including o shore sand ban s in the rish ea and along the south east coast their distribution is now reduced he ain stoc s occur in inner ralee ay alway ay ill hiar in ay in onne ara lew ay lac sod ay and ough willy
ur e et ds yster beds are surveyed annually by dredge redge designs vary locally and these locally pre erred dredges are used in the surveys redge e iciencies were esti ated in 0 0 by co parison o the nu bers o oysters caught in the dredge and the nu bers subse uently counted on the sa e dredge trac by divers i ediately a ter the dredge tow had been co pleted io ass is esti ated using a geostatistical odel accounting or spatial autocorrelation in the survey data
er ralee a t tre s io ass esti ates standardised to a dredge e iciency o varied ro a low o 0 tonnes in 0 to a high o over 000 tonnes in 0 0 and 0 0 he 0 survey esti ate is an outlier in the ti e series he area surveyed usually contains the entire stoc which is distributed over appro i ately able
e t s ss tre s r t e yster er r ee y e r t s r ey r ey re ( ) ss ss epte ber 0 epte ber 7 7 0 ebruary 0 epte ber 7 0 epte ber epte ber 7 0 epte ber 0 epte ber 7 0 epte ber 7 ctober 7 7 7 7 epte ber 0
r ey e te er ss s A pre ishery survey was carried out ro the 0th epte ber in nner ralee ay A total o 0 tows were underta en with a single toothless dredge o width data or each tow trac was recorded on a ri ble survey unit and swept area or each tow esti ated he survey enco passed an area o east and west o enit pier igure 7
io ass o oysters uncorrected or dredge e iciency varied ro 0 0 gs igure 7 io ass o oysters over 7 ranged ro 0 0 gs
otal bio ass o oysters assu ing a dredge e iciency o was tonnes able he e uivalent bio ass o oysters 7 or over was tonnes able or appro i ately o the total bio ass
e str t yster ss rre te r re e e e y er r ee y e te er ss (t es) s e e rre te r e e y io ass 7 7 io ass 7 0 0 rre te re e e e y io ass 00 7 io ass 7 n 7 7
7
re str t ss t e yster er r ee y e te er
e str t he si e distribution o oysters caught during the survey shows a strong ode at about 70 and a s aller ode at 0 igure he location o both odes is si ilar to that in 0 he substantially higher density at the 70 ode co pared to 0 cannot be e plained solely by growth he higher survey e ort in 0 0 and the di erences in the spatial distribution o the trac s co pared to 0 suggest the 0 0 survey is ore reliable
uture prospects or the stoc re ain strong given that all si e classes ro 0 7 are well represented in the stoc ortality rates on oysters below 7 appear to be low
re e str t t e ysters t e er r ee yster e e te er e ( ) s s s t re st r se t s e rt re r ess ts s t str t
ill iar i t tre s nly our surveys had been carried out by the arine nstitute on the ill hiar in oyster beds prior to ctober 0 0 and the surveyed area has varied each ti e able rior to 0 0 aighde ara eo and carried out surveys in 00 00 and 00 istorically the oyster beds in ill hiar in provided a steady return o 0 tonnes o native oyster per annu or uch o the 0s and in 0 tonnes were landed o e habitat anage ent clutching occurred at that ti e but ceased in
e t s ss tre s r t e yster r e r t r ey re ( ) ss ss ctober anuary 0 7 ctober 0 ctober 0 ctober 7 ctober 07
r ey O t er A survey was carried out on ctober st on the oyster beds o ill hiar in A total o tows were underta en 7 valid with a single toothless dredge o width 0 data or each tow line was recorded on a ri ble survey unit and swept area or each tow esti ated he survey enco passed a co bined area o and a total sa pling e ort o
ss io ass o oysters uncorrected or dredge e iciency varied ro 0 0 07 gs with the highest bio asses in the centre and south east beds o the study region igure io ass o oysters over 7 ranged ro 0 0 0 gs ollowing a si ilar distribution pattern
he bio ass o oysters assu ing a dredge e iciency o gives a total o tonnes able he e uivalent bio ass o oysters 7 or over the national ini u landing si e was tonnes able indicating that the bio ass o co ercial si e is 0 o the total stoc in the bay he dredge e iciency co e icient used was that recorded during the ill hiar in yster survey o 0 0 his dredge e iciency was esti ated along 7 separate trac s using divers to be
re str t ss t e yster r O t er ( rre te r re e e e y)
e ss t e yster r O t er se re e e e y ss (t es) s e e rre te r re e e y io ass strea edulis 7 0 7 7 7 io ass 7 0 7 0 0 rre te r re e e y io ass strea edulis 07 07 io ass 7 7 07 7
e str t he si e distribution o oysters caught during the 0 0 survey shows a very si ilar pattern to 0 igure 0 he odal si e was 0 in both years here was no evidence o in year recruit ent
he si e distribution data continues to show apparent high rates o ortality above 0 as shown by the reduced nu bers o oysters in the stoc above that si e ishing ortality should only contribute to reduced nu bers above 7 he strong ode at about 0 is evident in 0 0 and 0 0 here is no signal however that these si e classes are
70
progressing towards the ini u landing si e which would signi icantly increase the co ercial stoc si e he cause o this is currently un nown
re e str t t e ysters (Ostrea edulis) r O t er O t er e s e ( ) s s t re st r se t s e rt re r ess ts s t str t
u ill A survey o native and aci ic oysters involving stations was co pleted in ough willy in uly 0 0 using a single toothless dredge o width
t e Oyster (Ostrea edulis) t tre s he area covered by the surveys has varied signi icantly during the ti e series which co pro ises inter year co parisons able n general bio ass corrected or dredge e iciency o is between tonnes io ass was higher in 0 7 0 and 0 0 than previous years here was an average o tonnes in 0 0
e t s ss tre s r t e yster t y e r t r ey re ( ) ss ss arch 0 ove ber 07 ctober 77 ctober ctober 0 August 0 August 7 0 7 epte ber 7 April 7 07 uly 0 7
str t ss io ass o native oysters uncorrected or dredge e iciency and including all si es varied ro 0 0 0 7 gs Abundance and bio ass was higher in the southern part o the survey area igure io ass o oysters over 7 ranged ro 0 0 0 gs
7
he bio ass o native oysters assu ing a dredge e iciency o was tonnes able he e uivalent bio ass o oysters 7 or over the national ini u landing si e was tonnes or o the total stoc he si e distribution data indicates that ortality rates between 0 7 are high
re ss t e ysters y y ( rre te r re e e e y)
e str t t e yster ss rre te rre te r re e e e y y y t r yster e s ere e ss (t es) s e e rre te r re e e y io ass strea edulis 0 7 io ass 7 7 7 rre te r re e e y io ass strea edulis 7 7 io ass 7 7 0 7
e str t s he si e distribution o native oysters in the survey showed a strong ode at 0 with ew individuals above the 7 ini u landing si e here was no indication o recent recruit ent
7
re e str t t e ysters y y ( rre te r re e e e y)
yster ( a alla a i as) str t ss io ass o paci ic oysters uncorrected or dredge e iciency varied ro 0 0 gs with the highest bio asses in the south and north west o the survey area igure
re ss ysters y y ( rre te r re e e e y)
he bio ass o paci ic oysters assu ing a dredge e iciency o gives a total o 7 tonnes able 7 he previous esti ate in 0 was tonnes
7
e str t yster ss rre te rre te r re e e e y y y t r yster e s ere e ss (t es) s e e rre te r re e e y io ass 0 7 rre te r re e e y io ass 7 70 7
e str t s he si e distribution o aci ic oysters in the survey indicate a strong ode at 0 hese are probably year old oysters spawned in 0
here has been a decline in the prevalence o larger si e classes o aci ic oysters since 0 n 0 7 and 0 two ain cohorts were present odel si es o about and 0 igure he larger cohort was not as evident in the 0 0 survey igure his reduction is probably due to ishing he si e distributions however also show active annual recruit ent o aci ic oysters in the area
re e str t yster e te er r y
7
re e str t yster y y
7
A
Glossary r y A easure o how close an esti ate is to the true value Accurate esti ates are unbiased e t An ani al living on or in the sea loor ( stre ) A parasite o native oyster which in ects the blood cells and causes ortality o oysters ss easure o the uantity eg etric tonne o a stoc at a given ti e e A ilter eeding ollusc with two shells eg scallops coc les rt ( s ) ish which were born in the sa e year syste s are composed of living animals, plants and non living structures that exist together and ‘interact’ with each other cosyste s can be very s all the area around a boulder they can be ediu si ed the area around a coral ree or they can be very large the rish ea or even the eastern Atlantic t t r te he proportion o a population at the beginning o a given ti e period that is caught during that ti e period usually e pressed on a yearly basis or e a ple i 7 0 000 ish were caught during the year ro a population o illion ish alive at the beginning o the year the annual e ploitation rate would be 0 7 s rt he total ishing gear in use or a speci ied period o ti e s rt ty eaths in a ish stoc caused by ishing usually reported as an annual rate s ery roup o vessel voyages targeting the sa e asse blage o species and or stoc s using si ilar gear during the sa e period o the year and within the sa e area e g the rish lat ish directed bea trawl ishery in the rish ea Also re erred to as a etier s e es A te porary entitle ent issued to the owner o a registered ishing vessel to ta e part in co ercial ishing eet ty A easure o the physical si e and engine power o the ishing leet e pressed as gross tonnage s and ilowatts s eet e e t he ishing leet register or the purpose o licencing is organised in to a nu ber o groups seg ents r t er s educed yields o ish due to reduction in average si e weight age caused by ishing ortality and indicating that the rate o ishing is higher than the rate at which ish grow to given si es to replace those being re oved e e t is an agreed plan to anage a stoc ith de ined ob ectives i ple entation easures or harvest control rules review processes and usually sta eholder agree ent and involve ent e e t ts A geographic area encompassing a ‘population’ of fish de lineated or the purpose o anage ent ay be a pro y or or a realistic re lection o the distribution o the stoc e ( ) he ini u body si e at which a ish ay legally be landed t r A geographic area with particular ecological eatures or species designated under the abitats or irds irectives uch eatures or species ust not be signi icantly i pacted by isheries t r rt ty eaths in a ish stoc caused by predation illness pollution old age etc but not ishing y e t A type o ishing licence ntitle ents associated with these licences are generally broad and non speci ic essels with such licences are in the polyvalent seg ent o the ishing leet re s A easure o how variable repeated easures o an underlying para eter are t A portion o a total allowable catch A allocated to an operating unit such as a essel class or si e or a country e r t e t he a ount o ish added to the e ploitable stoc each year due to growth and or igration into the ishing area or e a ple the nu ber o ish that grow to beco e vulnerable to the ishing gear in one year would be the recruit ent to the ishable population that year his ter is also used in re erring to the nu ber o ish ro a year class reaching a certain age or e a ple all ish reaching their second year would be age recruits e r t e t er s he rate o ishing above which the recruit ent to the e ploitable stoc beco es signi icantly reduced his is characterised by a greatly reduced spawning stoc a decreasing proportion o older ish in the catch and generally very low recruit ent year a ter year
7
A
r o s arious reference points can e defined for fished stoc s hese can e used as a management target or a management trigger i e point here more stringent management action is re uired xamples include fishing mortalit rate reference points, iomass reference points, indicator eg catch rate reference points or those ased on iological o servations al s o s nformation on the volume and price of fish recorded for all first point of sale transactions ll s olluscan, crustacean or cephalopod species that are su ect to fishing o os o he distri ution, in si e, of a sample of fish usuall presented as a histogram otal Allo a le atch r A fishing vessel, usuall fishing for cra , ith a sea ater tan s elo dec s, in hich the catch is stored live essel onitoring stem essels report position periodicall hen fishing o A conservation measure used in lo ster fisheries in reland and else here here lo sters mar ed ith a v notch are protected from fishing
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