next message in archive
no next message in thread
previous message in archive
Index of Subjects
> This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. --Boundary_(ID_Y6RfyKsWijB8dURzf1BFRA) Content-type: text/plain; charset=ISO-8859-1 Content-transfer-encoding: quoted-printable Chris, your informative note omits the fact that the Green Crab was discovered in Newfoundland recently -- there was a note to that effect on the TV news perhaps back in July or so of this year?? Also, I believe that one of its bad effects on ecosystems is the uprooting of eel grass during its foraging for young bivalves etc. David Garbary of St. F.X. Univ. has done some studies of this. Cheers from Jim in Wolfville ---------- From: c.majka@ns.sympatico.ca Reply-To: naturens@chebucto.ns.ca Date: Mon, 08 Oct 2007 09:26:01 -0300 To: naturens@chebucto.ns.ca Subject: [NatureNS] Green Crab Hi Gayle, Th green crab (Carcinus=A0maenas), originally a Palearctic (old world) species, was first detected in North America in 1817. It is now globally dispersed, occurring in=A0Australia, Hawaii, Sri Lanka, South Africa, along the Atlantic and Pacific coasts of North America, and the Atlantic coast of South America. In eastern North America it is now found from Nova Scotia south to Virginia. On the Pacific coast it was first found in San Francisco in 1989 and now occurs from California north to British Columbia.=A0 The green crab has had a negative impact on soft-shell clams, young oysters= , and native crabs in the northeast since the 1950s. There have been significant impacts to commercial fisheries and natural ecosystems.=A0 Green crabs have been implicated in the destruction of the soft-shell clam (Mya arenaria) fisheries in New England and the reduction of populations of othe= r commercially important bivalves including the scallop (Argopecten irradians= ) and the northern quahog (Mercenaria mercenaria).=A0 In Connecticut, weekly rates of crab predation on scallops were as high as 70% leading researchers= ) to conclude that green crabs were responsible for most observed mortality i= n scallops and that the green crab was "one of the worst, if not the worst, clam predators we know." Lafferty and Kuris (1996) estimated commercial fishery losses in the United States resulting from green crab predation at $44 million dollars. Green crabs eat a wide variety of prey and can significantly reduce populations o= f native clams and crabs in areas where they have become established.=A0 Their ability to out-compete native species for food resources, high reproductive capacity,=A0 and wide environmental tolerances lend them the capacity to fundamentally alter community structure in coastal ecosystems. For more information about this species see the USGS page at: http://nas.er.usgs.gov/queries/FactSheet.asp?SpeciesID=3D190 , where there are references and links to many other sources of information a= s well. All the best! Chris=20 On 8-Oct-07, at 8:56 AM, Gayle MacLean wrote: Hello Bernard, =A0 Beside one of the photos of the Green Crab (River Bourgeois, Cape Breton), you have in brackets, "alien species". Was that because of its posturing stance or because it has been introduced and not native to the area, and if so, would it be considered a pest? =A0 Thanks, =A0 Gayle MacLean, Dartmouth PS: Beautiful photographs, BTW, as are all of the pictures that are posted by the members of this group!! Bernard Burke <blburke@ns.sympatico.ca>=A0wrote: Hi all =A0 Here are some updated photos=A0to the site with a few mixed in=A0from my sister Rita and her husband, and one by Murray Newell of the Solitary Sandpiper he mentioned in his posting.=A0This new group of photos=A0starts with a Wren and ends with a Spruce Grouse (from # 63 to # 73). Here is the first one: =A0 http://bernieb.smugmug.com/gallery/916397/4/46469808/Medium =A0 Cheers =A0 Bernard Burke blburke@ns.sympatico.ca Dartmouth Be smarter than spam. See how smart SpamGuard is at giving junk email the boot with the=A0All-new Yahoo! Mail _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._. Christopher Majka - Nova Scotia Museum of Natural History 1747 Summer Street, Halifax, Nova Scotia, Canada=A0 B3H 3A6 (902) 424-6435 =A0 Email <c.majka@ns.sympatico.ca> _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._. --Boundary_(ID_Y6RfyKsWijB8dURzf1BFRA) Content-type: text/html; charset=ISO-8859-1 Content-transfer-encoding: quoted-printable <HTML> <HEAD> <TITLE>FW: [NatureNS] Green Crab</TITLE> </HEAD> <BODY> Chris, your informative note omits the fact that the Green Crab was discove= red in Newfoundland recently -- there was a note to that effect on the TV ne= ws perhaps back in July or so of this year?? Also, I believe that one = of its bad effects on ecosystems is the uprooting of eel grass during its fo= raging for young bivalves etc. David Garbary of St. F.X. Univ. has don= e some studies of this.<BR> <BR> Cheers from Jim in Wolfville<BR> ----------<BR> <B>From: </B>c.majka@ns.sympatico.ca<BR> <B>Reply-To: </B>naturens@chebucto.ns.ca<BR> <B>Date: </B>Mon, 08 Oct 2007 09:26:01 -0300<BR> <B>To: </B>naturens@chebucto.ns.ca<BR> <B>Subject: </B>[NatureNS] Green Crab<BR> <BR> Hi Gayle,<BR> <BR> Th green crab (<I>Carcinus=A0maenas</I>), originally a Palearctic (old world)= species, was first detected in North America in 1817. It is now globally di= spersed, occurring in=A0Australia, Hawaii, Sri Lanka, South Africa, along the = Atlantic and Pacific coasts of North America, and the Atlantic coast of Sout= h America. In eastern North America it is now found from Nova Scotia south t= o Virginia. On the Pacific coast it was first found in San Francisco in 1989= and now occurs from California north to British Columbia.=A0<BR> The green crab has had a negative impact on soft-shell clams, young oysters= , and native crabs in the northeast since the 1950s. There have been signifi= cant impacts to commercial fisheries and natural ecosystems.=A0 Green crabs ha= ve been implicated in the destruction of the soft-shell clam (<I>Mya arenari= a</I>) fisheries in New England and the reduction of populations of other co= mmercially important bivalves including the scallop (<I>Argopecten irradians= </I>) and the northern quahog (<I>Mercenaria mercenaria</I>).=A0 In Connecticu= t, weekly rates of crab predation on scallops were as high as 70% leading re= searchers) to conclude that green crabs were responsible for most observed m= ortality in scallops and that the green crab was "one of the worst, if = not the worst, clam predators we know."<BR> <BR> Lafferty and Kuris (1996) estimated commercial fishery losses in the United= States resulting from green crab predation at $44 million dollars. Green cr= abs eat a wide variety of prey and can significantly reduce populations of n= ative clams and crabs in areas where they have become established.=A0 Their ab= ility to out-compete native species for food resources, high reproductive ca= pacity,=A0 and wide environmental tolerances lend them the capacity to fundame= ntally alter community structure in coastal ecosystems.<BR> <BR> For more information about this species see the USGS page at:<BR> <BR> http://nas.er.usgs.gov/queries/FactSheet.asp?SpeciesID=3D190 , <BR> <BR> where there are references and links to many other sources of information a= s well.<BR> <BR> All the best!<BR> <BR> Chris <BR> <BR> <BR> <BR> On 8-Oct-07, at 8:56 AM, Gayle MacLean wrote:<BR> <BR> <BLOCKQUOTE>Hello Bernard,<BR> =A0<BR> Beside one of the photos of the Green Crab (River Bourgeois, Cape Breton), = you have in brackets, "alien species". Was that because of its pos= turing stance or because it has been introduced and not native to the area, = and if so, would it be considered a pest?<BR> =A0<BR> Thanks,<BR> =A0<BR> Gayle MacLean, Dartmouth<BR> PS: Beautiful photographs, BTW, as are all of the pictures that are posted = by the members of this group!!<BR> <BR> <B><I>Bernard Burke <blburke@ns.sympatico.ca></I></B>=A0wrote:<BR> <BLOCKQUOTE><FONT SIZE=3D"2"><FONT FACE=3D"Arial">Hi all<BR> </FONT></FONT>=A0<BR> <FONT SIZE=3D"2"><FONT FACE=3D"Arial">Here are some updated photos=A0to the site = with a few mixed in=A0from my sister Rita and her husband, and one by Murray N= ewell of the Solitary Sandpiper he mentioned in his posting.=A0This new group = of photos=A0starts with a Wren and ends with a Spruce Grouse (from # 63 to # 7= 3). Here is the first one:<BR> </FONT></FONT>=A0<BR> <FONT SIZE=3D"2"><FONT FACE=3D"Arial">http://bernieb.smugmug.com/gallery/916397= /4/46469808/Medium<BR> </FONT></FONT>=A0<BR> <FONT SIZE=3D"2"><FONT FACE=3D"Arial">Cheers<BR> </FONT></FONT>=A0<BR> <FONT SIZE=3D"2"><FONT FACE=3D"Arial">Bernard Burke<BR> blburke@ns.sympatico.ca<BR> Dartmouth<BR> </FONT></FONT></BLOCKQUOTE><BR> <BR> <HR ALIGN=3DCENTER SIZE=3D"1" WIDTH=3D"100%"><BR> Be smarter than spam. See how smart SpamGuard is at giving junk email the b= oot with the=A0<B>All-new Yahoo! Mail<BR> </B></BLOCKQUOTE><BR> <BR> <BR> <FONT FACE=3D"Times">_._._._._._._._._._._._._._._._._._._._._._._._._._._._.= _._._._._._._._._.</FONT> <BR> <BR> <FONT FACE=3D"Times">Christopher Majka - Nova Scotia Museum of Natural Histor= y</FONT> <BR> <BR> <FONT FACE=3D"Times">1747 Summer Street, Halifax, Nova Scotia, Canada=A0 B3H 3A= 6</FONT> <BR> <BR> <FONT FACE=3D"Times">(902) 424-6435 =A0 Email <c.majka@ns.sympatico.ca></= FONT> <BR> <BR> <FONT FACE=3D"Times">_._._._._._._._._._._._._._._._._._._._._._._._._._._._.= _._._._._._._._._.</FONT> <BR> <BR> <BR> </BODY> </HTML> --Boundary_(ID_Y6RfyKsWijB8dURzf1BFRA)--
next message in archive
no next message in thread
previous message in archive
Index of Subjects