Submarine Dive Video
The Diversity and Distribution of Cephalopods in the Charlie-Gibbs Fracture Zone Richards JC1*, Vecchione M1,2
1Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution2National Marine Fisheries Service, National Museum of Natural History, Washington DC, 20560, USA
References1. Cook A.B, Sutton T.T, Galbraith J.K, Vecchione M, 2012, ”Deep-pelagic (0–3000m) fish
assemblage structure over the Mid-Atlantic Ridge in the area of the Charlie-Gibbs Fracture
Zone”, Deep Sea Research Part II, 98: 279-291
2. GeoMapApp: http://www.geomapapp.org
3. Ryan et al., 2009
4. Clarke, KR (1993). Non-parametric multivariate analyses of changes in community structure.
Australian Journal of Ecology 18: 117-143
5. Vecchione M, Young R.E, and Piatkowski U, 2010, “Cephalopods of the northern MidAtlantic
Ridge”, Marine Biology Research, 6: 1, 25 – 52
6. v7: Clarke, KR, Gorley, RN, 2015. PRIMER v7: User Manual/Tutorial. PRIMER-E, Plymouth,
296pp.
AcknowledgementsWe thank April Cook for providing the discrete-depth zones and their volume calculations. We thank Abby Reft
for assisting with specimens. We thank NOAA for providing ship time and support for the 2009 Bigelow Cruise
and the 2004 SARS Cruise. We Thank Elizabeth Cottrell for mapping with GeoMapApp. A special thanks to the
Smithsonian Institution. All data are associated with the MARECO program of the Census of Marine Life. Funding
was provided by NSF.
IntroductionThe majority of the oceans still remain unexplored. For this reason, the MARECO project of the
Census of Marine Life explored biodiversity along the Charlie-Gibbs Fracture Zone (CGFZ):
the region of the Mid-Atlantic Ridge running from Iceland to the Azores.
Cephalopods play an integral part in marine environments, where they take on both predator
and prey roles. Cephalopods are also important within the fishing industry. The distribution
and diversity of cephalopods was quantified in order to learn more about the ecosystems
surrounding the CGFZ.
Muusoctopus johnsonianus Gonatus steenstrupi Mastigoteuthis agassizii
Sampling Sites
0 m
700 m
200 m
1900 m
2900 m
Ocean FloorBottom
Mid Water
North
America
Africa
Charlie Gibbs Fracture Zone
Eleven sites along the CGFZ were
sampled. Each site consisted of two
major trawling zones: Mid water and
bottom. The mid water zone is further
broken up into four discrete depth
ranges: 0 – 200 meters, 200 – 700
meters, 700 - 1900 meters, and 1900
– 2900 meters.1 Roughly 20 species of
cephalopod were collected across all
sites.
9 11 13
12
15
18
17
16
2019 21
Atlantic Ocean
MethodsSite DiversitySubmarine Dive Video
Squid Abundances Site Similarity
50 hours of video across 11 dives were viewed.
Sightings of the most common species, Gonatus
steenstrupi, were recorded alongside the time of
day and depth. Dive data is separate from trawl
data.
The total number of species recorded at each
site via trawling was mapped using
GeoMapApp. Each site was divided between
mid water and bottom trawling zones.
The total number of Gonatus steenstrupi caught
at all sites via discrete depth trawling was
standardized by the total water filtered at each
depth. Trawls were divided temporally (e.g. Day
and Night). Only mid water depth ranges were
used for these calculations.
The species composition (number of individuals of
each species) at each site was compared to other
sites with Bray-Curtis Similarity.6 These similarity
values were used to produce tree diagrams.5 Each
site was categorized as north or south and divided
between mid water and bottom.
0
1000
2000
12:00 AM 6:00 AM 12:00 PM 12:00 AM 6:00 PM
Gonatus steenstrupi ROV sightings
Dep
th (m
ete
rs)
Squid
Sighting
Conclusion:
Gonatus steenstrupi are most common closer to the ocean surface; the majority live
above depths of 1000 meters.
Graph depicting 11 separate dives and their distinct paths; red points signify the sighting of a
Gonatus steenstrupi. Blue represents day and purple represents night.
NightDay
Site Diversity
Squid Abundances Site Similarity
04 1284
Night Day
2900
700
1900
200
0
Abundance (Squids/104 m3 water)
Gonatus steenstrupi Diel Abundances
Dep
th (m
ete
rs)
Conclusion:
Gonatus steenstrupi display the highest abundances during the day and at
shallower depths.
Juvenile G. Steenstrupi
collected during trawls
Day vs. Night (i.e. Diel) graph depicting G. steenstrupi abundances at various depths.
Charlie Gibbs Fracture Zone
Mid Water Site Diversity
Charlie Gibbs Fracture Zone
Bottom Site Diversity
Number of
Species
present:
1
3
5
8
Maps depicting the number of species present at each site. Each site is divided into
two zones: mid water and bottom. Blue signifies a northern site and red signifies a
southern site.
Mean North
Diversity: 2.4
Mean South
Diversity: 4.75
Mean South
Diversity: 3.25
Mean North
Diversity: 3.5
Squid Species
Showcase:
Conclusion:
Mid waters in southern sites have the highest diversity and mid
waters in northern sites have the lowest diversity.
0
20
80
100
60
40
20 21 1715 16 919 1213 1118
Sim
ila
rity
(%
)
Mid Water Site Similarity
Sim
ila
rity
(%
)
0
20
80
100
60
40
19 11 13 15 20 9 21 17
North
South
Legend:
Bottom Site Similarity
Octopod
Species
Showcase:
Tree depicting similarity (%) amongst the mid water trawl zones of sites.
Tree depicting similarity (%) amongst the bottom trawl zones of sites.
0%
40%
22%
32%
46%
56%
71%
14%11%
30%
43%
62%
80%
63%
79%89%
96%
Conclusion:
Mid water sites are more similar than bottom sites.
Photograph courtesy of David Shale, MARECO Photograph courtesy of David Shale, MARECO Photograph courtesy of David Shale, MARECO
North
South
Legend: