\ceanological and Hydrobiological Studies, VOL. 51, NO. 2 | JUNE 2022 
Katharina Romoth, Mavva Goaina, Kolia Beisienel Alexander Darr, Michael Lothar Zettle 
GLOSSARY 
iOW - Leibniz Institute for Baltic Sea Research 
Warnemünde 
MPA - Marine Protected Area 
1. Introduction 
The common sun star Crossaster papposus (L. 1767) 
is a conspicuous and distinctive species. The generic 
designation of this species has historically alternated 
between Solaster and Crossaster, both belonging to 
the family Solasteridae (Ringvold & Moum 2020). 
Crossaster papposus shows a wide circumboreal 
distribution and is recorded mainly on the continental 
shelf in temperate waters (Ringvold & Moum 2020), 
out is also found at depths ranging from the low 
intertidal zone to 1200 m (Clark & Downey 1992). The 
species is widely distributed in the Pacific, the Atlantic 
Icean and occurs all around the British Isles up to 
the southern North Sea (Djakonov 1950; Grainger 
1966; Himmelman & Dutil 1991; Harms 1993; Carlson 
& Pfister 1999; Gaymer et al. 2004). In the German 
part of the North Sea, finds of C. papposus come 
from stone reefs in the eastern German Bight, but 
are mainly documented for the island of Helgoland 
Rachor et al. 2013). Habitat preferences vary from 
zoarse sand or gravel to rock bottom, mussel and 
ayster beds (and from the infralittoral fringe down 
to deep circalittoral habitats). A three-year study 
recording sublittoral communities around Helgoland 
oroved the occurrence of C. papposus in one of the 
aight hard bottom communities, with a prevalence 
9f 17% at the sampled locations (de Kluijver 1991). 
Moreover, the species occurs sporadically in the Great 
and Little Belt as well as in the Kattegat (Hayward & 
Ryland 1990; Clark & Downey 1992; Gonschior 2016), 
the transition areas connecting the North Sea with 
the Baltic Sea. Despite increasingly intensive mapping 
and monitoring efforts over the last decades, as well 
as yearly monitoring cruises by the Leibniz Institute 
for Baltic Sea Research Warnemünde (IOW) since 2009, 
the last observations of C. papposus in the German 
Baltic waters date from before 1900 (Zettler et al. 2018; 
see additional file 1). 
The common sun star is nationally protected under 
the German Federal Ordinance on the Conservation 
af Species (BArtSchV). Annex 1 to BArtSchV lists 
native protected species of fauna and flora whose 
oopulations are threatened by human interference, 
and Crossaster papposus is classified as a Sstrictly 
N ı 
pandhs.uy.edu.pl 
protected species (81 sentence 2; BArtSchV 2005). The 
accurrence of C. papposus has been better recorded in 
recent decades mainly due to the use of underwater 
video imaging. Therefore, the species has been moved 
from category 1 (threatened with extinction) to 
category 2 (highly endangered) on the national Red 
List (Rachor et al. 2013). 
2. Materials and method; 
The observations reported in the present study 
were collected on 21 April 2019 and 27 June 2021 
during mapping and monitoring activities prescribed 
by the Habitats Directive and relevant to the 
implementation of the Marine Strategy Framework 
Directive. The common sun star C. papposus was found 
in both cases at the Natura 2000 site “Fehmarn Belt” 
(EU-Code: DE 1332-301) in the south-western Baltic 
Sea (54°34.41934’N; 10°50.06339’E and 54°35.48544’N; 
10°54.82932’E; Fig. 1). The area is protected under 
national law since 2017. However, while management 
plans have recently been released, no actual 
management measures have yet been implemented 
at the time of drafting this paper. The Natura 2000 
site is heavily impacted by vessel traffic, and intensive 
bottom trawling continues in its boundary areas (BfN 
(Ed.) 2020). 
8 
Germany 
= 
10°50'E 
11°0'E 
m ml 
11°10°'E 11°20'E 
441536 * 
54°35'N+ 
S4°300 > 
Fenmar 
Figure 1 
Location of the study area: (a) Map of Northern Europe 
showing the location of the ”Fehmarn Belt” Marine 
Protected Area (MPA), (b) the MPA between Denmark 
and Germany, historical and recent records of Crossaster 
papposus in the area of interest, and (c) the records of 
C. papposus in the designated reef area. 
ournal owner: Facultv of Oceanoaraphv and Geoaraphv. Universitv of Gdansk. Polancı