1. Assessing the distribution & diversity of Kuril-Kamchatka abyssal plain & Okhotsk Sea deep-sea fauna

2. FORMER SPONGE RESEARCH IN THIS REGION
150 years of sponge sampling in NW Pacific
Collections mainly from Russia & Japan
200 spp. distribution records collated from older publications and OBIS
INTRODUCTION METHODOLOGY RESULTS DISCUSSION

3. NEW SAMPLING IN THIS REGION
KuramBio and SokhoBio expeditions:
Twenty-two stations were sampled
Depths range from m.
Sponges were collected using an Agassiz trawl (AGT), Epi-benthic sledge (EBS), and box-corer (GKG).
INTRODUCTION METHODOLOGY RESULTS DISCUSSION

4. TAXONOMY & DATA COLLECTION
Collating North Pacific Ocean sponge distribution records
Standard methodology
INTRODUCTION METHODOLOGY RESULTS DISCUSSION

5. DIVERSITY & ENDEMISM
>100% increase (20 spp.)
Increases in the number of abyssal species in this sector of NW Pacific
New to science species
Endemism
29% spp. new to science (11 spp.)
55% spp. endemic (21 spp.)
26% increase (8 spp.)
Kurile-Kamchatka
Okhotsk Sea
No. of Spp. 31
37+
35% spp. endemic (11 spp.)
21% spp. new to science (3 spp.)
INTRODUCTION METHODOLOGY RESULTS DISCUSSION

6. RARITY & ABUNDANCE X 8 more specimens from Okhotsk than KKT
>60% species limited to 1 stn.
X 8 more specimens from Okhotsk than KKT
19% of previously known species not re-found
74% hexactinellid
Species rarity is common
Hexactinellid abundance – often high in biomass
>50% species limited to 1 stn.
83% of previously known species not re-found
43% hexactinellid
INTRODUCTION METHODOLOGY RESULTS DISCUSSION

7. DEPTH RANGES DEPTH INTRODUCTION METHODOLOGY RESULTS DISCUSSION
OKHOTSK SEA
KURILE-KAMCHATKA
DEPTH
EURYBATHY
55% spp. eurybathyic
57% spp. eurybathyic
SUBMERGENCE?
67% demosponge spp. eurybathyic
<50% demosponge spp. eurybathyic
>70% hexactinellid spp. eurybathyic
>70% hexactinellid spp. eurybathyic
INTRODUCTION METHODOLOGY RESULTS DISCUSSION

8. UNUSUAL NW PACIFIC ABYSSAL CHARACTERISTICS
Dominance of demosponge species; not typically seen in abyssal fauna
Carnivorous sponges (Cladorhizidae) dominate demosponge spp. & genera richness
Global importance of carnivorous sponges
70% of spp. demosponges
Cladorhizids: >50% of demosponge spp.
72% of spp. demosponges
15-20% of cladorhizids found in this NW Pacific sector
Cladorhizids: 87% of demosponge spp.
INTRODUCTION METHODOLOGY RESULTS DISCUSSION

9. CONNECTIVITY IN NW PACIFIC
Okhotsk-N/NW Pacific = 45%
East Kamchatka Current
Strong connections found throughout abyssal NW Pacific sponge fauna
Importance of straits & sub-Polar gyres & currents
Strong abyssal connectivity found between semi-enclosed Okhotsk Sea and open NW Pacific Ocean: Hex vs. Demo
KKT-N/NW Pacific = 65%
Okhotsk Sea Gyre
Aleutian - Okhotsk = 30%
W. Sub-Arctic Gyre
STRAITS
Alaskan Stream
Oyashio – Sub-Arctic Current
Kuroshio – North-Pacific Current
INTRODUCTION METHODOLOGY RESULTS DISCUSSION

10. PROCESSES DRIVING RICHNESS & ENDEMISM
Sponge richness is potentially aided by:
Isolation – Okhotsk 36 Ma
Extreme environmental changes
Productivity
Low population densities
Heterogeneity
INTRODUCTION METHODOLOGY RESULTS DISCUSSION