Ai-Ping Chiang, Hui-Ling Lin, and Tai-Chun Lin

1
Ai-Ping Chiang, Hui-Ling Lin, and Tai-Chun Lin
Institute of Marine Geology and
Chemistry National Sun Yat-sen University
Kaohsiung, TAIWAN 804
2
Outlines
Introduction
Study area
Results and discussions
Conclusions
3
Introduction

• Studies of dead and living benthic foraminifera
  had shown that the organic carbon content in
  sediments, is the main factor controlling the
  distribution patterns and morphologic variations
  in benthic fauna (Corliss and Chen, 1986 Loubere
  and Gray, 1990 Jannink et al., 1998 Jorisson et
  al., 1998 Jorissen, 1999 Dulk et al., 1998,
  2000).

• Other studies have demonstrated the sensitivity
  of the assemblage composition to changes in
  oxygen levels of the bottom water and within the
  sediment. As a result, the general contention is
  that oxygen and food supply are the main factors
  controlling the spatial and in-sediment
  distribution of benthic foraminifera. (Jorissen
  et al., 1995)

4
Introduction
Therefore, the goal of this study is to examine
what controls the spatial distribution of benthic
foraminifera in Kao-ping Submarine Canyon in
southwest Taiwan.
5
Introduction
South China Sea
6
Taiwan Strait
Introduction
Kaoping Submarine Canyon
Kao-ping River
Pacific Ocean
This submarine canyon extends almost immediately
seaward from the mouth of the Kao-ping River down
to the lower continental slope over a distance of
240 km (Yu et al., 1993 and Liu, 2002). It
eventually terminates in the northwestern corner
of the South China Sea basin. This submarine
canyon was considered the seaward continuation of
the Kao-ping River (Yu et al., 1991).
7
Introduction
Kao-ping River
3-dimensional view of the sea-floor near the head
of Kao-ping Submarine Canyon. The water depths
are represented by the color bar.
From http//140.117.94.1/liu/index.htm
8
Study area
Kao-ping River
Locations of study area
9
Results and discussions
Analysis items
1?TOC (total organic carbon)
2?Abundance of benthic foraminifera
3? Living (stained)/total benthic shells ratio
(for each individual species)
10
Benthic foraminifera abundance and TOC
11
Station N1
12
Station N2
13
Station KP1-KP5
14
Station S1
15
These results suggest that variations in total
organic carbon contents do not preferentially
affect benthic foraminifera abundance.
16
Living (stained)/total benthic shells ratio
(for each individual species)
The purpose of Rose Bengal is to stain organisms
that were alive at the time of collection. (Hess
et al,2001)
Hess and Kuhnt (1996) used the ratio of living
specimens to the total abundance of species to
determine the succession of recolonizers,
assuming that species with high numbers of dead
individuals probably colonized earlier than
species with higher numbers of living individuals.
17
Stained/total ratio
18
(No Transcript)
19
Stained/total ratio
20
(No Transcript)
21
Stained foraminifera aboundance
22
Stained/total ratio
In view of the higher stained/total ratio and
lower dead tests, we are inclined to interpret
the appearance of stained benthic foraminifera in
the head of Kao-ping Submarine Canyon as the
effect of migration, rather than caused by
differential reproduction or differential
mortality.
23
What causes the effect of migration?
Arrows in this diagram represent the existence of
transport directions according to the McLaren
Model analysis plotted over the 3-D bathymetry of
the study area. Each line of arrows represents a
predetermined orientation of transport. The
isobaths are in meters. (Liu et al. 2002 )
24
Conclusions
This study is the first report regarding the
stained benthic foraminifera in Taiwan,
especially in the region of Kao-ping Submarine
Canyon, off the southwest island. Different from
previous studies, the spatial distribution of
stained benthic foraminifera seems not to be
related with TOC contents in sediments.
The higher stained/total ratio and lower dead
tests at the head of Kao-ping Submarine Canyon
than adjacent area might be the effect of
migration, which could be resulted from complex
interaction between tides and currents.
25
Thank you for your attention