Estimating historical trawling effort in the German Bight from 1924 to 1938

Patterns of extirpation. I. Changes in habitat use by thornback rays Raja clavata in the German Bight for 1902-1908, 1930-1932, and 1991-2009

“…interference, forced it to final extirpation. This is supported by estimated historical trawling distributions (Fock 2014) indicating that part of the area oc cupied by thornback rays in 1930− 1932 was less intensively traw led than surrounding areas ('d' in Fig. 4).…”

“…This underpins the role of fisheries in determining the distribution of thornback rays, as evidenced by the significant range reduction indicated during the 3 periods 1902−1908, 1930−1932, and 1991−2009 with almost 0 abundance during the latter period. Fishing mortality is driven by a considerable increase in fishing power in the area, ranging from relatively low values and 17% of untrawled area in 1902−1908, to high fishing pressure in 1991(ter Hofstede & Rijnsdorp 2011, Fock 2014). The range reduction for thornback rays coincided with a change in habitat use, and significant differences were indicated between habitat models for 1902−1908 and 1930−1932 in terms of sediment parameters applied in either model.…”

“…pdf) developed in the 1920s and increased fishing pressure in the coastal area. This particular increase (Fock 2014) could be the cause for a weaker presence of thornback rays in coastal waters in the period 1930−1932 ('c' in Fig. 4), causing the stock to move into off-coastal and more northerly areas.…”

How governance impacts non-timber forest product value chains in Cameroon

“…During the 19 th century, the fishery expanded in the wake of the industrial revolution, steam-powered vessels replacing sailing vessels (Engelhard, 2008;Smith, 1994). In the 20 th century, fishing pressure further increased as a result of a large array of technological innovations that increased fishing power of individual vessels (Fock, 2014;Lescrauwaet et al, 2010;Kerby et al, 2012;Rijnsdorp et al, 2008).…”

Patterns of extirpation. II. The role of connectivity in the decline and recovery of elasmobranch populations in the German Bight as inferred from survey data

“…Distributions were calculated for the periods 1902−1908 and 1930−1932 to reveal changes from the earliest period with limited fishing effort and about 17% of untrawled ground to the period after which commercial fisheries had increased considerably (Fock 2014a). In the area under investigation, utilization of poorerquality habitat under increased fishing pressure was evidenced for thornback ray (Fock 2014b …”