CEFAPARQUES Project

Identification and characterization of preferential habitats to cephalopods of commercial interest

New insights for a more suitable resource management

Participants

IIM (CSIC, Vigo) & IMEDEA (CSIC, Palma de Mallorca)

Ángel Guerra. Research coordinatorÁngel F. González Beatriz Morales - NínManuel E. Garci Miguel Cabanellas - ReboredoJorge Hernández - Urcera Matias Calvo-ManazzaAlex Chamorro Miquel Palmer

CEFAPARQUESParque Nacional de las

Islas Atlánticas de Galicia (PNIAG)

Parque Nacional de Cabrera (PNC)

Project duration: April 2012- November 2014 Results: April 2012 – April 2014

PNIAG

Octopus vulgaris spawning habitat

O. vulgaris juvenile / subadult habitat

O. vulgaris den ecology

Cannibalism in the wild

PNIAG: Spawning habitat and zone

PNIAG: spawning habitat and area

April 2012 – April 2014

• 73 grids of 33.2 Ha each

• 24 grids sampled

• 5-25 m depth

• 4 visual censuses (surveys) per month

• A total of 97 surveys

EST= Time of effective samplingDt= total immersion timeA= Time to get surfaceRt= recording time

EST = Dt - (A + Rt)

NSD = EST x ADS

PNIAG: visual censuses

NSD = net distance of samplingADS = diving estimated velocity

SAC = NSD x [HV x (Nd + 1 )]SAC= swept area HV= horizontal visibilityNd= nº divers

A new sampling method to estimate the swept area

PNIAG: spawning habitat and zoneTwo-three diversImages recorded (14 hours). Substrate composition

GPSCTD: Oceanographic parameters

GAMs: habitat characterization (season, depth, temperature, chlorophyll, substrate, predators, fishing impact … ) presence/absence of egg masses and spawning nests

PNIAG: spawning habitat and zone

The highest probability of occurrence of spawns and dens for females O. vulgaris nesting (spawning nests) were obtained in the north zone of the Cíes islands and during spring-summer season

Egg clusters: 24Female spawning nests : 54

Cíes Islands

Preferential spawning area and season

NorthSpring-Summer

PNIAG: spawning area

Recommendation: Total Protection inside the MPA (58 ha 5.8 % of total

marine Cíes realm) in that season

First step for O. vulgaris ecosystem approach to fishery management

PNIAG: spawning habitat and zone

Females behavior during reproduction: recorded and described

Aquí va el video de la hembra cuidando la puesta, no puedo enviarlo por email porque ocupa demasiado espacio

PNIAG: juveline-subadult habitatRodas inlet = Sand seabed30 ha, 5-21 m depth4 divers

3 visual surveys in June 2013 (O. vulgaris fishery season closed)1 survey in October 2013 (O. vulgaris fishery season open)

Recorded data:• Depth • Bottom temperature• Presence/absence in den• Octopus size • Bivalves in the midden• Den diameter

PNIAG: juvenile-subadult habitat

PNIAG: juvenile-subadult habitat

No statistical differences in occupation rate between both (closed or open) fishing seasons (VC1-VC2-VC3 and VC4)

VC: visual census number SA: swept area (m2)D: average depth (m) APD: area per den (m2)OD: occupied densARDO: average rate of occupancy (%)D/1000: mean number

VC DR DF ARDO DDA ± SD

1,2,35.0-10.0 27 92,6 19,4 ± 8,61

10.0-15.0 6 50 14,83 ± 6,24

  5.0-10.0 9 100 17,44 ± 5,08

4 10.0-15.0 6 50 16,83 ± 5,81

  15.0-21.0 5 40 17,6 ± 3,51

VC S A D APD OD ARDO D/1000

1 3330 11 302,73 10 90,91 3,302 2910 14 207,86 11 78,57 4,813 2350 8 293,75 7 87,50 3,404 5145 20 257,25 14 70 3,89

DR: depth range (m)DF: number of dens found ARDO: average rate of occupancy (%) DDA: den diameter average (cm)SD: standard deviation

Visuals surveys in Rodas inlet

Dens data in Rodas inlet

PNIAG: juvenile-subadult habitat

Prediction of a den occupied by an octopus: Decreased with z

Partial effect of depth in presence/absence of octopus in a den: Decreased with z

16 Kg octopus in the Park

PNIAG: juvenile-subadult habitat• Preferred habitat: SBT 15 – 16 ºC and

SBS ≈ 36.0• Depth 5-21 m, maybe related with:

⁻ prey presence, specially bivalves

⁻ Soft bottoms with bioclast

• Presence of double and triple dens in Rodas asocial? Further studies needed

This area should be also protected

1170 juveniles O. vulgaris in Rodas inlet between 5-21 m depth. (1.12% of the Cíes marine area)

• Den typology: A. Dug den in soft

sediment and reinforced with shells

B. Dug den under a rock

C. Empty shell or carapace

D. Human wastes

PNIAG: Dwellers in dens on sandy bottoms: Ecological and behavioral traits

of Octopus vulgaris

PNIAG: den ecologyShell collection: bivalves in the middens: old and none of then drilled. Main food : razors (Ensis arcuactus)

PNIAG: den ecology

- Deep holes reinforced with Pecten maximus

- Shells collected at the mouth of the hole

were old with algae, polichaetes and bryozoan incrustation

- Large and well build holes were occupied by small octopuses

- The middens were 3 times larger the hole size

Permanent dens

PNIAG: Cannibalistic behavior

Cannibalism has been observed and registered

three times within PNIAG

• Inter-cohort cannibalism• Both males and females are cannibal• Arms were the first part of the body

eaten• Other preys were abundant in the

surrenders• Predator was 20-25 % larger than prey

PNIAG: General conclusions for O. vulgaris

• The inner submarine area of the Cíes Islands is an Essential Fish Habitat for O. vulgaris.

• Two habitat and zones: one of breeding and spawning and other of growth will be proposed to the National Park authorities to be protected.

• Useful tool for resources management of commercial interest (ecosystem approach).

• Informative and educational documentary: Goods and services of a marine protected area.

http://www.cefaparques.tk/

PNIAG: Sepia officinalis

MES T D TfE F M A M J J A S O N D

P 4 9 5 7 1 5 31 10-15

11-14

E 4(2) 3(2) 4(2) 6(2) 8(2) 1(1) 12(2) 2(2) 3(2) 21(2) 4(2) 2(2) 1(3)

71

P= egg-layingE= individuals registered and size (1:<90 mm LM, 2: 91-180, 3: >180)D= deep (m)Tf = Bottom temperature (ºC)

PNIAG: Sepia officinalis

Surveys of S. officialis in the inner side of the Cies Islands . Total of 71, 58 % close Viños islet

Egg-laying Winter-spring time (in gorgonians and spirograph

PNIAG: Loligo vulgaris

Registered once

PNC National Park of Cabrera

Results only for Loligo vulgaris

No egg laying Sepia or OctopusPredator pressure (Epinephelus marginatus)

PNC Spawning areas

30 DACs Dispositives for egg layingRecovered one a month (june 2012 june 2013)

141 egg laying associated collected and counted

PNC Spawning areas

Zero-Inflated Poisson (ZIP)(Number of egg laying per DAC per month)Variables:• Habitat• Depth• SST• SSC• Presence/absence of Lepas

anatifera, currents…

Spatial distribution of egg masses Loligo vulgaris for DAC

Spawn all year, spring peak (may)

242 egg masses, 72,3 % in DAC in sand floors

15-50 m deep ( avoid surficial waters, above all sin summer)

PNC Spawning areas

All year spawning:• surficial waters in winter • deep waters in summer

spawning migrations

PNC Spawning areas

PNC Spawning areas

DAC: useful technique to characterize L. vulgaris habitatSpawning area depends on ocean bottom, deep, SST

Spawning peak maybe related with mesozooplankton availability

Migration for spawning

Management improvement: temporal - spatial closure of the fish area