2015 504:657667http://dx.doi.org/10.1007/s12601-015-0060-y Available online at http://link.springer.com pISSN 1738-5261 eISSN 2005-7172 Article Marine Environmental Impact Assessment of
Trang 1Ocean Sci J (2015) 50(4):657667
http://dx.doi.org/10.1007/s12601-015-0060-y
Available online at http://link.springer.com
pISSN 1738-5261 eISSN 2005-7172
Article
Marine Environmental Impact Assessment of Abalone, Haliotis discus hannai,
Cage Farm in Wan-do, Republic of Korea
Hyun-Taik Oh1*, Rae-Hong Jung2, Yoon-Sik Cho3, Dong-Woon Hwang2, and Yong-Min Yi1
1 Marine and Fisheries Environmental Impact Assessment Center, National Institute of Fisheries Science (NIFS), Busan 46083, Korea
2 Marine Environment Research Division, National Institute of Fisheries Science (NIFS), Busan 46083, Korea
3 Coastal Wetland Research Institute, National Institute of Fisheries Science (NIFS), Gunsan 54014, Korea
Received 22 February 2015; Revised 10 August 2015; Accepted 30 August 2015
KSO, KIOST and Springer 2015
Abstract To assess the marine environmental impacts of abalone,
Haliotis discus hannai, cage farms in Wan-do, we monitored the
benthic environment on top of the sediment underneath cage farm
stations and reference stations We applied two methods for this
assessment One was the A- and B-investigation of the MOM system
(Modeling – On fish farm – Monitoring) developed in Norway
The other was a general environmental monitoring method which
is widely used In this study, we found benthic animals in all samples
that belonged to condition 1 which were based on group 1(presence
of macrofauna) of the B-investigation method The values of redox
potential (group 2 – pH, redox potential) in all samples were above
+65 mV belonging to condition 1 Based on sensory results (group
3 – gas, color, odor, thickness of deposits), five out of seven experiment
samples showed condition 1 while stations 2 and 7 showed condition
2, which have been cultured for 10 years in semi-closed waters As
group 2 takes precedence over group 3, the level of the conditions
for B-investigation results consequently showed condition 1 in all
stations We found that pollutants and trace metals in the sediment
underneath cage farms were lower than the pollution standard This
led us to conclude that the environmental impacts of the cage farms
in this study were not significant
Key words environmental impact assessment, abalone cage
farm, MOM, benthic environment
1 Introduction
Concerns about the marine environmental impact of fish
farms have grown as marine pollution caused by fish farming
has increased Marine cage farming affects the marine
environment in a variety of ways In general, the impact of
fish cage farms is more serious than that of shellfish cage farms like abalone cultures and long-line cultures like oysters and clams This is due to overfeeding, nutrient loading of individual organisms, and waste from fish farm facilities (Silvert 1992; Naylor et al 2000; Sarà et al 2004) The enrichment of organic materials both from fish and abalone cage farms may cause the reduction of demanded oxygen (DO) in lower levels of water, not only generating a high concentration of acid-volatile sulfide (AVS) in sediment, but changing benthic communities around the farms (Yokoyama 2002, 2003; Kalantzi and Karakassis 2006) The environmental impact assessment (EIA)
of cage farms has been studied and monitored in Africa, Asia-Pacific, Europe, and America with different specialized methods for each case (FAO 2009) The highest application
of EIA to cage farms has been found in the finfish aquaculture industries of salmon, seabream, sea bass, and tuna around Europe and also in shellfish and seaweed farming in Europe, Norway, Australia, and China (Hansen et al 2001; Crawford et
al 2003; Borja et al 2009; Zhang et al 2009)
A report from the Food and Agriculture Organization (FAO) of the United Nations documented that the Norwegian Modeling – On fish farming – Monitoring (MOM) is reliable, fit for the purpose, and is cost-effective to assess the marine environmental impact of cage culture (FAO 2009) Even though the MOM system was developed primarily as an environmental impact assessment tool for fish cage farming, it is based on the general parameters for proper marine environmental management of cage farms, including finfish, shellfish, and seaweed culture (Zhang et al 2009) The MOM has A-B-C investigation methods according to temporal and spatial features
*Corresponding author E-mail: ohtek@korea.kr
Trang 2The A-investigation is a monthly or seasonal measurement
of the sedimentation rate of the organic material underneath
a cage farm It provides fish-farmers with immediate information
regarding the load as a part of their internal control routines,
which do not have any environmental quality standards
(Hansen et al 2001) The B-investigation is performed annually
or biannually in the local impact zone, and combines benthic
communities from Group 1, the pH-redox potential from
Group 2, and sensory parameters from Group 3 The
C-investigation is performed from the intermediate impact zone
to the regional impact zone, and is the study of a benthic
community structure (Ervik et al 1997; Maroni 2000) The
frequency of monitoring depends on the degree of environmental
impact For A-investigation and B-investigation, the frequencies
of monitoring are every month, every 2nd month, every 3rd
month and twice a year, every year, every 2nd year, respectively
Abalone, Haliotis discus hannal, production in South
Korea soared to 1,065 tons in 2003 from 85 tons at the
beginning of 2000 thanks to the development of net cage
technology which is a coastal water-based culture (Park and
Kim 2013) The cost of abalone farming is generally much
cheaper than that of land-based culture In 2011, Korea
produced 6,800 tons of abalone and it was the second largest
amount in the world Jeollanam-do is the leading producer
of abalone, accounting for 99% of the total production in S
Korea Located within Jeollanam-do, Wan-do produces
about 94% of this total and this is why the island is called the
Mecca of the abalone industry in Korea The gravest threat
to the abalone industry in Wan-do is the increasing mortality
rate The reasons for the increasing mortality rate are very
complicated and diverse Causes include: deteriorated currents
due to the densely distributed farms, depleted-oxygen due to
long-chained farms and seaweed Vulnerability caused by
storms and typhoons during the summer also contributes to
this problem Nonetheless, most of the studies that have
been conducted have focused on the environmental impact
of fish farming and research on shell farming has seldom
been carried out
In this context, this study is aimed at evaluating the impacts
of bio-deposits excreted by abalone and fall-offs of seaweed
in the benthic environment using the Norwegian MOM system
at a variety of licensed abalone farms in Wan-do Through
this experiment, we aim to determine two things Firstly, we
will determine the immediate quantification of the benthic
environment on site using the B-investigation methods
Secondly, we will collect detailed environmental information
including the condition of benthic communities and the concentration of pollutants and trace metals underneath abalone farms through laboratory analysis
2 Data and Methods
Study sites
The study sites are located in Wan-do, Jeollanam-do, in the southern seas of the Korean peninsula The sampling stations for the benthic environmental assessment are underneath the abalone cage farms near Saengil-do and Geumil-do (Fig 1) The average depth of the study sites are approximately 18
m, and the depth of each station and license information are shown in Table 1 The field trip for sediment sampling and investigation on site took place between November 1 and November 3, 2013 The tidal range in Wan-do is about 2 m and the sea water is exchanged by the tide through open channels The average velocities of the currents are between 89.2 cm·s-1 and 93.9 cm·s-1 (Yang 2011) Around these islands, sea-farmers have developed abalone culture facilities next
to seaweed farms since 2003 with the supplementation of abalone seedling production in the waters (Park and Kim 2013) As the abalone eat the abundant forms of seaweed
such as kelp, Saccharina japonica, and undaria, Undaria pinnatitida, Wan-do has become an optimal location for
abalone farms since the early 2000s
Sampling and analysis
For this study, 9 stations for benthic samples and investigation were selected on the basis of the period of time they had been involved in abalone aquaculture Taking vessel tracks into account, we chose 3 stations in possession of licenses for abalone aquaculture for almost 9–10 years (1, 2, 7) and 4 stations that were in possession of the same licenses for 4–6 years (3, 4, 5, 6) (Table 1) We chose two reference stations which were neither utilized for abalone culture nor seaweed culture in the inner waters (8) and on the way to a channel (9) Samples for the benthic environmental assessment were
in accordance with MOM B-investigation data and were collected at abalone farms (1 to 7) and reference stations (8
to 9) by a van Veen grab (0.05 m2) Using the first collection
of the samples, we monitored the pH-redox potential and sensory parameters on site, and then moved those samples to
a sieve and added two more collections for the macrofauna abundance experiment (0.15 m2) Finally, benthic samples were sieved with a 1-mm mesh sieve, checked for remaining
Trang 3macrofauna left on the sieve, and then preserved for laboratory
analysis and macrofauna classification In addition, the
unsieved sediment samples were preserved on site and
transferred to the laboratory to analyze the total organic
carbon (TOC, mg·g-1), total nitrogen (TN, mg·g-1), ignition
loss (IL, %), and trace metals such as Arsenic (As, mg·kg-1),
Cadmium (Cd, mg·kg-1), Chromium (Cr, mg·kg-1), Copper
(Cu, mg·kg-1), Lead (Pb, mg·kg-1), Zink (Zn, mg·kg-1) and
IL, and TOC based on the standard experimental method for
the marine environment For the analysis of trace metals,
dried samples were digested in a mixture of HNO3, HF and
mass spectrometer (ICP-MS, Perkin Elmer Elan-6000) at the National Institute of Fisheries Science (NIFS) The recovery rates for the target heavy metals in the standard reference materials were reasonably good (82–100%)
MOM modeling
In each station, we followed the scoring system of the MOM B-investigation and this generally means that the lower the score is, the better the benthic environment is, following the Norwegian Standards Association (Ervik et al 1997; Hansen et al 2001) For macrofauna, we assigned a score of
0 if materials remaining on the mesh screen contained macrofauna, or 1 otherwise For the investigation of the benthic
Fig 1 (a) The research site in Wan-do and sampling stations for experiment (#1–#7) and reference (#8–#9), (b) The sampling station of
abalone cage farms and the research vessel, (c) abalone net cage culture
Table 1 The information of sampling stations including license number, first date of license, name of species for culture, renew date, area of
farms, and water depth (* indicates 9–10 years old abalone cage farms)
No License No License Date Species Renew Date Area(Ha) Depth(m)
#1 11711 2003-06-24 * Net cage (Abalone) 2013-06-23 3 20
#2 12076 2004-09-23 * Net cage (Abalone) 2015-09-22 5 15
#7 11792 2004-08-10 * Net cage (Abalone) 2014-08-09 4 20
Trang 4communities underneath the abalone farms, a qualified
taxonomist investigated the macrofauna species Based on
the observation results of the pH and redox potential at 2 cm
depth in all sites, we assigned the score of 0, 1, 2, 3, and 5 in
accordance with the Norwegian standards(Schaanning and
Hansen 2005) Sensory parameters such as outgassing, color,
smell, consistency, grab volume and the thickness of deposits
were scored 0, 1, 2 or 4 depending on the extent to which a
parameter is affected by organic enrichment The more the
sediment is affected by organic materials, the higher the
score assigned to the sensory parameters (Table 2) The
analysis of the aforementioned parameters is shown in Table
2 below
3 Results
Group 1 (benthic community)
The group 1 parameter is a determinant of whether sediment
samples contain macrofauna or not Macrofauna were found
in all of the samples from all stations after sieving through a 1-mm mesh sieve, so all sites were given the score of 0 which means that circumstances at all stations were acceptable or satisfactory The mean score of all the samples at the study sites was 0, indicating that the group 1 condition was normal
at the study sites The most abundant species at each sample station were polychaetes A total of 41 polychaetes were identified
with Paralacydonia paradoxa, Sternaspis scutata, Amaeana occidentalis, Cirrophorus branchiatus and Flabelligeridae unid making up the majority, and their appearance frequencies
were 67%, 78%, 44%, 44% and 56%, respectively (Table 3) The number of the species in each station ranged from 4–18 per 0.15 m2 The highest quantities were found at the inner sites near the islands (#5, #7, #8) The lowest quantity was found at the reference station #9 in the open channel where
we could take only small sediment samples due to strong currents and hard consistency with no cage farms around Even if a taxonomist could classify the lowest number polychaete species at sampling station 9, its evaluated
Table 2 Environmental monitoring methodology of both Norwegian MOM investigation A-B and general environmental monitoring in
Korea
A-Investigation Sedimentation rate mm/year Value
B-Investigation
Group 1 (Presence of macrofauna) ind./0.15m2 Presence = 0 Absence = 1 mean score 0.5: condition 1, 2 or 3
mean score > 0.5: condition 4
Group 2
0, 1, 2, 3, 5 (Schaanning and Hansen, 2005)
mean score 1: condition 1
1 < mean score 2: condition 2
2 < mean score 3: condition 3
mean score > 3: condition 4
Group 3 (Sensory parameters)
Outgassing Quantitative assessment of
gas bubbles
Absence = 0 Presence = 4
mean score < 4: condition 1
4 mean score < 10: condition 2
10 mean score 14: condition 3
mean score > 14: condition 4
Color Subjectivevisual
assessment
Pale/Gray = 0 Brown/Black = 2
Smell Subjectiveolfactory
assessment
None = 0 Medium = 2 Strong = 4 Consistency Subjectivetactile
assessment
Firm = 0 Soft = 2 Loose = 4 Grab volume Quantitativeassessment of
grab volume
< 1/4 = 0 1/4 ~3/4 = 1
> 3/4 = 2 Thickness of
deposits
Quantitative assessment of seposits
< 2 cm = 0
2 ~ 8 cm = 1
> 8 cm = 2 General
investigation
Sedimentary parameters (TOC, TN, IL) Concentration TOC, TN : mg
-1
IL : % Trace metals (As, Cd, Cr, Cu, Pb, Zn, Hg)Concentration mg kg-1
Trang 5sediment condition was still based on group 2 and 3,
showing that nutrient concentration and trace metals were
still good (Table 4, Table 5)
The Shannon-Wiener index ranged between 1.91–3.92
Table 3 The macrofauna abundance (ind./0.15 m2) at experiment sites (#1#7) and reference sites (#8#9)
Level of condition (1~3) (1~3) (1~3) (1~3) (1~3) (1~3) (1~3) (1~3) (1~3)
Paraonis glacilis japonica 15
Diversity index 2.61 2.91 2.65 2.93 3.53 2.04 3.92 3.38 1.91
Trang 6which indicated that the conditions of all stations in our study
were better than those of shellfish and seaweed farming areas in a
similar study (1.8–2.3) carried out in China (Zhang et al
2009) Group 1 and polychaete community results revealed
that there were not any significant differences between sampling
stations in terms of the number of species, as the results of
ANOVA showed that the significance probability was above
0.05 Overall, the sediments underneath abalone cage farms
in the study sites were still in an acceptable or satisfactory
condition
Group 2 (chemical values)
Group 2 parameters for the Norwegian B-investigation
are based on the measurement of pH and redox potential
ascertained by inserting electrodes into the sediment (Hansen et
al 1997) The pH and redox potential in the sediment was measured immediately after the samples were collected from a depth of 20 mm at all stations The pH and redox potential (Eh) values ranged between 7.71–8.09 and 65.0–135.1 mV, respectively The assigned scores based on the pH and redox potential values are 0 (#4, #6, #7, #8, #9) and 1 (#1, #2, #3, #5), so the level of the conditions at all sites is 1 (Table 4) Scores for the pH and redox potential were analyzed 0 or 1 according to
a previous study by Schannig and Hansen (2005), and the scores were applicable to all sampling stations for condition
1 This was based on group 2 of the B-investigation method Even though the values of reference stations (#8, #9) were higher than those of the experimental stations (#1–#7), the
Table 4 The pH and redox potential values, concentration of nutrients, and trace metals in the sediment
B-Investigation
(Group 2)
redox potential mV 99.5 79.9 85.2 115.5 65.5 110.5 105.5 135.5 130.5
Sedimentary
parameters
IL % 5.47 5.58 4.46 5.78 3.58 5.16 5.21 5.61 5.45
TN mg·g-1
1.45 1.41 0.71 1.35 0.45 1.15 0.95 1.25 1.15 TOC mg·g-1 10.31 9.95 5.51 9.85 3.35 8.31 6.95 9.35 7.85
Sediment grain
Silt % 50.1 48.2 36.6 33.2 43.6 53.6 56.1 40.7 53.1 Clay % 48.8 51.0 58.2 65.3 29.1 43.3 41.2 53.8 45.0
Harmful
substances
As mg·kg-1 6.78 6.66 6.01 6.93 5.34 5.99 6.14 5.29 6.12
Cd mg·kg-1
0.03 0.05 0.04 0.03 0.03 0.05 0.03 0.05 0.03
Cr mg·kg-1 50.19 52.39 49.81 53.38 40.13 48.14 57.95 51.37 54.02
Cu mg·kg-1
16.95 18.14 14.72 18.39 11.81 16.31 17.72 17.13 17.41
Pb mg·kg-1 25.73 26.72 22.37 27.41 19.78 22.45 26.96 23.43 24.07
Zn mg·kg-1
86.17 90.42 80 92.41 64.19 96.6 89.86 85.13 85.3
Hg mg·kg-1 0.02 0.015 0.008 0.014 0.008 0.013 0.013 0.014 0.014
Table 5 Sensory results both for abalone cage farm stations (#1–#7) and reference stations (#8–#9)
Trang 7differences were trivial and all values were mostly
concentrated in the border of 0 and 1 According to the group
2 result, the environmental conditions in all stations meet the
standards for a well-oxygenated marine environment with
low organic input and favorable conditions for the presence
of benthic communities Our measurements were not made
at different levels of depth but only at a depth of 20 mm to
examine the systematic pH and redox potential differences
between farming grounds and reference stations
The sand, silt, and clay amounts or ratios were collected
underneath the cage farms using a ternary figure based on
the Shepard classification scheme (Shepard 1954) The average
composition of gravel, sand, silt and clay were recorded as
0%, 5.5%, 46.1% and 48.4% respectively (Table 4) The
sediments mostly consisted of silty clay and clayish silt
except at station 5 which was primarily made up of sand at
27.3% The grain size ranged between 6.2–9.2 Ф which
means that it consisted of very fine silt which was mostly
clay The sorting values and skewness values ranged between
3.0–3.4 Ф and -0.3–0.9, which means very poorly sorted and
very coarse skewed, respectively The sorting kurtosis showed
very leptokurtic curves with the value of 1.6–2.4 Our study
sites have cultured abalone since 2004, but the sedimentary
composition has not yet been affected by abalone cage
farms
The concentration of sedimentary parameters such as IL
(%), TN (mg·g-1), and TOC (mg·g-1) ranged between 3.58–
5.78%, 0.45–1.45 mg·g-1, 3.35–10.30 mg·g-1 respectively
The values of IL were mostly within the range of 5.1–5.8%,
but station 5 had the lowest value of 3.58% due to its higher
composition of sand at 27.3% At station 9, both the TN and
TOC concentrations were lower than those at other stations,
too
Results indicated that the finer the sediment, the higher the
concentration of pollutants This is similar to the results of
other related studies conducted at the surface sediment of
cage farms (Matthaei et al 2006) In Japan, if the concentration
of TOC is above 10.3 mg·g-1 in a fish farm, the responsible
local authority would issue a warning to farmers to take action
to preserve the marine environment according to environmental
quality status (EQS) (Yokoyama 2003) In Europe, if the
concentration of TOC is lower than 11.9 mg·g-1, farmers get
a “Good” or “High” rating based on the European EQS (Bakke
et al 2010) If the TOC standard of Europe was applied to
abalone cage farms in this study, the values of TOC in all
stations would have been lower than the standard, which indicates
that sediment conditions are quite good The concentrations
of TOC in most of stations were lower than the standards applied in Japan except for station 1 (10.31 mg·g-1) where the cage culture has been established since 2003 These parameters
at the cage farms did not reveal any significantly lower values than those at the reference stations (Table 4) We found that sedimentary environmental conditions in 8 out of 9 stations were still good based on the standards of Japan, and all stations were still environmentally healthy according to European standards
The trace metals in the sediment are measured to check the safety of the abalone cage farming grounds In this study, the content of trace metals such as As, Cd, Cr, Cu, Pb, Zn and Hg were measured underneath cage grounds and reference stations According to the United States National Ocean and Atmosphere Administration (NOAA)’s reference tables for trace metals in sediment, the critical values of effect range low (ERL) for As, Cd, Cr, Cu, Pb, Zn and Hg are 8.2 mg·kg-1, 1.2 mg·kg-1, 81.0 mg·kg-1, 34.0 mg·kg-1, 46.7 mg·kg-1, 150.0 mg·kg-1 and 0.15 mg·kg-1 respectively (Buchman 2008) The values for harmful substances at all stations were lower than those of the sediment quality guidelines (SQGs) This suggests that the impacts of trace metals on benthic communities were negligible The study sites in Wan-do were also found not to be significantly polluted by harmful substances, and healthy sediment conditions had been maintained The As value of station 4 was below the standard but close to the threshold (85%), so more studies are required to identify the potential causes of metal pollution in abalone cage farms (Table 4)
Group 3 (sensory values)
Group 3 parameters of the B-investigation show many sensory variables representing organic enrichment such as gas ebullition, color, odor, consistency and thickness of sludge The results of sensory parameters are shown in Table 5 Outgassing was not found in any of the sample stations, so
we assigned an on- site score of 0 to them The colors of sample sites were gray (score = 0) except at station 7 which was brown-black (score 2) There was no smell from the sediment samples, but there was a slight sulfide smell from station 7 The consistency of the sediment was soft and gentle (score = 2), but station 9 was hard (score = 0) Mostly, the grab volume was not greater than 3/4 except at station 2 which got a full volume grab The thickness of sludge accumulated
on top of the original sediment ranged between 0.6–1.5 cm,
Trang 8so we a score of 0 was assigned for all stations The total
scores of group 3 in the B-investigation ranged from 1–7,
with station 7 with the highest score and station 9 with the
lowest score A sum less than 4 falls into condition 1 while
the sum equal to or greater than 4 and less than 9 falls into
condition 2 Therefore, the level of condition based on the
sum of scores was condition 1 for (#1, #3, #4, #5, #6, #7, #8)
and condition 2 for (#2, #7) (Table 5)
As a whole, general conditions were given by the results
of the group 1, 2, 3 of the B-investigation Most sample
stations (#1, #3, #4, #5, #6, #8, #9) showed the same level of
conditions with both group 2 and 3 containing macrofauna
Therefore, we determined that the general condition of
stations 1, 3, 4, 5, 6, 8 and 9 were 1 However, samples from
station 2 and 7 were different from group 2 and 3 If they are
different, group 2 takes precedence over group 3 (Ervik et al
1997; Hanse et al 2001) Therefore we determined that the
general conditions of station 2 and 7 were 1 because the
condition of the station is determined by group 2 (Table 6)
We found that sedimentary environmental conditions in all
sites were still good judging by the concentration of IL, TN and TOC, even though the value of TOC in station 1 was similar
to the value of standard applied in Japan for marine environmental fish farm preservation In Wan-do, the concentrations of trace metals were below the limit of ERL, which indicates that the environment is still clean (Table 4)
4 Discussion
The increasing age of a farm is likely related to worsening conditions
Abalone cage farms in Wan-do, Jeollanam-do have been intensely developed since the early 2000s with the development
of net cage technology in coastal waters With the increasing abalone mortality rate, farmers have become seriously concerns about the environmental impacts of the abalone cage farms and the densely distributed facilities in a limited site area
Table 6 General level of condition of the sediment in Wan-do
Sedimentary condition Normal Good Good Good Good Good Good Good Good Trace metals (ERL) None None None None None None None None None
Fig 2 The results of pH and redox potential based on previous
measurements from various cage farms in Europe (Schanning
and Hansen 2005)
Fig 3 Ternary diagram for sedimentary composition around cage
farm in Wan-do
Trang 9Meanwhile, a marine environmental monitoring program
by the NIFS has been undertaken in the coastal waters of S
Korea Even though there are a number of observation
stations, they are not close to the abalone farms in Wan-do
The nearest station of the NIFS is located 3.2 km to the north
and 4.7 km to the west of the abalone cage farms in this
study To assess the marine environmental impacts of cage
farms, regular monitoring is needed directly underneath
cage farms because the impacts of sedimentary parameters
should be measured within 30 to 50 m of cage centered
grounds In this study, we concluded that the general conditions
underneath abalone cage farms were pretty good, though the
values of some stations were a little higher than those of the
reference stations In particular, the 10 year-old licensed
cage farms (stations 2 and 7) showed the level of condition
2 according to the sensory parameters of the B-investigation
method Also, the value of TOC at station 1, a 10 year-old
licensed cage farm, was higher than the standard applied at
fish farms in Japan (Yokoyama 2003) More extensive and
regular interdisciplinary studies in close proximity to abalone
cage farms are required to investigate the potential pollution
of bio-deposits excreted by abalone, fall-off from seaweed,
and harmful substances in the sediment Without the environmental
impact assessment of abalone cage farms, a local authority
cannot take prompt action to determine the causes of unexpected
deaths among abalone cultures which may be related to
oxygen-depletion and environmental changes
K-MOM necessity
The MOM system was developed for the assessment of
the marine environmental impacts of intensive marine fish
farming in Norwegian waters (Ervik et al 1997) It covers the
environmental impacts not only in local and intermediate
zones through the A and B investigation methods but also in
intermediate and regional zones by C-investigation methods
And it allows for an immediate assessment to be carried out
on site and can be conducted easily and the results sent to the
laboratory for analysis by professionally skilled technicians
and taxonomists This convenient method allows local
fishermen to receive the training to carry out the measurements
The general concept of the MOM system is based on a general
assessment of the marine environment regardless of the
species being reared or cultivated Both fish cage farming
and abalone cage farming have similar impacts on the benthic
environment, even though fish cage farming affects the
marine environment in a slightly more detrimental manner
than abalone cage farming To date, most of the researches conducted have been focusing on fish farming However, environmental problems have started to occur in the abalone cage farming industry and this has led to a decrease in productivity We have ascertained that the environmental impact around abalone cage farms in Wan-do can also be assessed using this system We assigned a score range to a schematic assessment map based on our observation results
To use this pH-redox potential method frequently, we need
to collect more measurements from several more culture grounds Measurements need to be made at different levels
of depth in core samples, and then the lowest pH and the corresponding redox potential should be used to assign scores The group 3 parameters provide reliable information
on sediment conditions Visual observation is also a good way to obtain valuable information on the marine environment, but it has been underestimated as an adequate tool to obtain measurement results with respect to sedimentary parameters and trace metals More extensive studies on sensory parameters are required to improve them as a reliable method This can
be accomplished through a questionnaire survey by experts based on a dataset Eventually, we need to put in place Korea – MOM (K-MOM) to properly evaluate the licensed culture farms
Better understanding of hydrodynamics
The marine environmental impacts of cage farms are closely related to farming locations (Karakassis et al 2000) The stronger the current is, the less polluted the environment
is with fewer deposits of pollutants and pseudofaeces by abalone and the absence of excessive input of seaweed deposits underneath farms Densely distributed facilities of abalone cage farms and long-chained farms cause the slowing
of water flow and water exchange, especially in semi-closed waters Although we have data on average current speeds and tidal range from Wan-do, these are not reliable as they were not measured close to the cage farms In the study sites, the speed and patterns of currents as well as the amount of sea water exchanges could be one of the main reasons for variations in biological and chemical parameters, but those physical characteristics were beyond the scope of this study
On a national and regional level, the concerned authorities should consider those physical characteristics when they prepare the relocation of and new licenses for abalone cage farms in the near future Our knowledge of hydrodynamic conditions can help us better understand the parameters that
Trang 10are represented and where alternative farming sites should
be located
5 Conclusion
In this study, we evaluated the marine environmental impacts
of abalone cage farms using the MOM system and compared
sedimentary parameters and trace metals in Wan-do, S
Korea We found the general level of the condition which
was given by the results of group 1, 2, 3 of B-investigation
methods was 1 in all abalone cage and references stations
We found macrofauna in all stations The most abundant
species was polychaete with Sternaspis scutata, Paralacydonia
paradoxa, Cirrophorus branchiatus, Flabelligeridae unid
and Amaeana occidentalis as the major variety The pH and
65.0–135.1 mV, respectively The assigned scores based on
the pH and redox potential are 0 (#4, #6, #7, #8, #9) and 1
(#1, #2, #3, #5), so the level of conditions in all sites is 1 The
total scores of group 3 in the B-investigation ranged between
1–7, and the level of the conditions based on the sum of the
scores was condition 1 (#1, #3, #4, #5, #6, #7, #8) and
condition 2 (#2, #7) If group 2 and group 3 bring a different
result, group 2 takes precedence over group 3 Therefore, we
determined the level of the general condition as condition 1
We found that sedimentary environmental conditions are
still good in all sites judging by the concentration of IL, TN,
and TOC The concentration of the trace metals was below
the limit of ERL which indicates that the areas are in a good
environmental condition
Acknowledgements
This work is funded by a grant from the National Institute
of Fisheries Science (RP-2015-ME-036)
References
Bakke T, Källqvist T, Ruus A, Breedveld GD, Hylland K (2010)
Development of sediment quality criteria in Norway J Soils
Sediments 10(2):172–178
Borja Á, Rodríguez JG, Black K, Bodoy A, Emblow C, Fernandes
TF, Forte J, Karakassis I, Muxika I, Nickell TD, Papageorgiou
N, Pranovi F, Sevastou K, Tomassetti P, Angel D (2009) Assessing
the suitability of a range of benthic indices in the evaluation of
environmental impact of fin and shellfish aquaculture located
in sites across Europe Aquaculture 293(3–4):231–240
Buchman MF (2008) NOAA screening quick reference tables National Oceanic and Atmospheric Administration, Seattle, NOAA OR&R Report 08-1, 34 p
Crawford CM., Macleod CKA, Mitchell IM (2003) Effects of shellfish farming on the benthic environment Aquaculture
224(1):117–140
Ervik A, Hansen PK, Aure J, Stigebrandt A, Johannessen P, Jahnsen T (1997) Regulating the local environmental impact of intensive marine fish farming I The concept of the MOM system (Modelling-Ongrowing fish farms-Monitoring) Aquaculture
158(1):85–94
FAO (2009) Environmental impact assessment and monitoring in aquaculture FAO, Rome, FAO fisheries and aquaculture technical paper 527, 57 p
Hansen PK, Ervik A, Aure K, Johannessen J, Jahnsen P, Stigebrandt T, Schaanning A (1997) MOM Concept and revised edition of monitoring program 1997 Institute of Marine Research, Bergen,
51 p Hansen PK, Ervik A, Schaanning M, Johannessen P, Aure J, Jahnsen T, Stigebrandt A (2001) Regulating the local environmental impact
of intensive, marine fish farming: II The monitoring programme
of the MOM system (Modelling–Ongrowing Fish farms–
Monitoring) Aquaculture 194(1):75–92
Kalantzi I, Karakassis I (2006) Benthic impacts of fish farming: meta-analysis of community and geochemical data Mar Pollut
Bull 52(5):484–493
Karakassis I, Tsapakis M, Hatziyanni E, Papadopoulou KN, Plaiti
W (2000) Impact of cage farming of fish on the seabed in three
mediterranean coastal areas ICES J Mar Sci 57(5):1462–1471
Maroni K (2000) Monitoring and regulation of marine aquaculture in
Norway J Appl Ichthyol 16(4–5):192–195
Matthaei CD, Weller F, Kelly DW, Townsend CR (2006) Impacts
of fine sediment addition to tussock, pasture, dairy and deer
farming streams in New Zealand Freshwater Biol 51(11):2154–
2172 Naylor RL, Goldburg RJ, Primavera JH, Kautsky N, Beveridge MCM, Clay J, Folke C, Lubchenco J, Mooney H, Troell M (2000)
Effect of aquaculture on world fish supplies Nature 405:1017–
1024 Park CJ, Kim SY (2013) Abalone aquaculture in Korea J Shellfish
Res 32(1):17–19
Sarà G, Scilipoti D, Mazzola, Modica A (2004) Effects of fish farming waste to sedimentary and particulate organic matter
in a southern Mediterranean area (Gulf of Castellammare, Sicily):
a multiple stable isotope study Aquaculture 234(1):199–213
Schaanning MT, Hansen PK (2005) The suitability of electrode measurements for assessment of benthic organic impact and their use in a management system for marine fish farms In: Hargrave B (ed) Environmental effects of marine finfish aquaculture Springer, Berlin, pp 381–408
Shepard FP (1954) Nomenclature based on sand-silt-clay ratios J
Sediment Res 24(3):151–158