20

Part  B  -  Technical  instructions

Table  1.4:  Beam  trawl  survey  of  epifauna.

Baseline  study

Construction
phase

Operation  phase

Objectives

Description  of  epifauna  (macrobenthos, ­
  demersal  fish)  in  the
project  and  reference  areas.
Medium  and  small  scale  survey
of  status  quo,  to  be  used  as  a
basis  for  assessing  possible  impacts ­
  of  wind  turbines.

Medium  and  small  scale  survey  of
relevant  operation  phase  impacts
on  species  communities.

Scope

Once  a  year  in  autumn.  In  the  first  year  of  the  baseline  study,  description  of  seasonal
conditions  in  the  project  area  and  reference  area  requires  investigations  in  spring  and
in  autumn.

The  number  of  beam  trawl  per  area  (project/reference  area)  depends  on  the  number  of
assessed  infauna  stations  (see  Table  1.3).  Half  of  the  infauna  stations  have  to  be  surveyed ­
  by  means  of  beam  trawls.  In  smaller  areas  (<  20  nmi 2 ),  at  least  10  beam  trawl
surveys  should  be  conducted.

Timing

At  least  two  consecutive  and
complete  years  prior  to  construction ­
  start.

In  the  first,  third  and  fifth  year  of
the  operation  phase.

Method

Sampling  strategy:
•  The  sampling  dates  are  to  observe  the  same,  limited  time  frame  each  year.  The
sampling  interval  in  the  project  and  reference  area  must  not  exceed  2  weeks.
•  The  seasons  are  defined  as  follows:  Spring:  01.03.-15.05./Autumn:  15.08.-15.11.
•  Equipment  standard:  2  m  beam  trawl  (mesh  size  1  cm).  Duration  of  ground-level
trawling  should  be  5  min.,  trawling  speed  should  be  1-3  kn.
•  Documentation  of  the  sample  processing  method  has  to  be  provided
(according  to  ISO/DIS  16665).  The  condition  of  the  catching  device  must  be
documented.
•  Biomass  shall  be  determined  as  wet  weight  per  species
(according  to  ISO/DIS  16665,  Annex  C).
Moreover,  the  following  information  must  be  determined  and  documented:
•  Shooting  and  hauling  positions,  towing  time,  area  covered.
•  Hydrographic  (T,  Sal,  0 2 )  and  meteorological  data.

Presentation ­
  of
results

Documentation  of  condition  and  modification  per  project  and  reference  area
(described  in  separate  chapters)  by  illustration  of:
•  Total  number  of  individuals  per  area/number  of  individuals  per  species  and  area
(species  table).
•  Total  biomass  per  area/biomass  per  species  and  area.
•  Dominance  structure  (related  to  number  of  individuals  and  biomass).
•  Occurrence  and  distribution  of  Red  List  species.
•  Diversity/evenness  for  community  analysis,  cluster  analysis  or  multi-dimensional
scaling,  univariate  analyses,  significance  tests.
•  Evaluation  according  to  BACI  design  with  suitable  statistical  methods.