Table 1 List of species sequenced, including populations codes, sampling localities with respective geographical coordinates and substrata where they were taken

C. andreae

CAMOR

El Morche (Málaga) Spain

36°44′15″N, 3°59′38″W

Drifting rope

JX988565–JX988579, JX988596–JX988598

CAAZO

São Miguel (Azores), Portugal

37°48′28″N, 23°33′80″W

Drifting stick

JX988539–JX988552, JX988590–JX988592

CACOL

Columbretes (Castellón), Spain

39°51′19.2″N, 0°40′04.2″E

Drifting material

JX988557–JX988558

CAALB

Alboran Sea, Spain

35°56′26.35″N, 3°1′23.91″W

Caretta caretta (turtle)

JX988531–JX988538

CAFUE

Fuengirola (Málaga), Spain

36°33′14.37″N, 4°29′21.39″W

Caretta caretta (turtle)

JX988559–JX988564

CATUR

Seferihisar (Izmir), Turkey

38°11′32″N, 26°38′07″E

Caretta caretta (turtle)

JX988580–JX988582

CACHA

Charleston (Florida), USA

28°23′14.6″N, 80°32′38.8″W

Caretta caretta (turtle)

JX988553–JX988556, JX988593–JX988595

C. penantis

CPTAR

Tarifa Island (Cádiz), Spain

36°00′00.7″N, 5°36′37.5″W

Intertidal alga Asparagopsis armata

JX988583, JX988599

CPEST

Estepona (Málaga), Spain

36°25′28.79″N, 5°8′41.51″W

Intertidal alga Corallina elongata

JX988584, JX988600

CPCAST

Castelejo, Portugal

37°06′9.3″N, 8°56′46.7″W

Intertidal alga Gelidium sp.

JX988585, JX988601

CPALM

Punta Almina (Ceuta), Spain

35°54′2.52″N, 5°16′29.68″W

Intertidal alga Gelidium sesquipedale

JX988586

C. dilatata

CDALI

Guardamar (Alicante), Spain

38°05′1.10″N, 0°38′1.59″W

Fish farm

JX988587, JX988602

CDALG

Algeciras Bay (Cádiz), Spain

36°10′0.5″N, 5°24′36.82″W

On buoys (algae and bryozoans)

JX988588

CDPOR

El Portil (Huelva), Spain

37°12′43″N, 7°4′26.80″W

On buoys (algae and bryozoans)

JX988589, JX988603