Coast environment monitoring system

Abstract

To provide a coast environment monitoring system capable of evaluating the environmental status of a coast in a sea area taking into account a factor other than plants and algae.SOLUTION: A coast environment monitoring system according to the present invention comprises a measurement unit 1 equipped with multiple measuring instruments that measures dissolved oxygen concentration in seawater at multiple measurement points within a sea area, a primary production calculation unit 2 that calculates primary production generated by photosynthesis within the sea area based on the dissolved oxygen concentration measured by the measurement unit 1, a primary production estimation unit 3 that estimates the primary production at the current time under a condition relevant to primary production using previously acquired data or theoretical equations, an environmental condition determination unit 4 that determines the current environmental condition of the sea area based on the primary production calculated by the primary production calculation unit 2 and the primary production estimated by the primary production estimation unit 3 using a preset sea area environmental condition pattern, and a display 5 that outputs the determination result from the environmental condition determination unit 4.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a system for monitoring the coastal environment of a marine area. [Background technology]

[0002] In coastal areas of the ocean, seaweed, algae, and phytoplankton grow using nitrogen and phosphorus as nutrients supplied by inflow from land, elution from bottom sediments, and inflow from the open sea.

[0003] In recent years, carbon stored over long periods as organic matter through photosynthesis from dissolved carbon dioxide in seawater in seaweed beds and seaweed farms, known as blue carbon, has been attracting attention. Carbon storage is thought to occur through a number of mechanisms: the deposition of dead seaweed on the seafloor, the sinking of detached seaweed to the deep sea, the secretion of persistent organic matter from seaweed, seaweed, and phytoplankton, and the biodegradation of easily degradable organic matter secreted by seaweed, seaweed, and phytoplankton, as well as its sinking to the deep sea (where biodegradation proceeds slowly due to the oligotrophic and oxygen-deficient environment). Furthermore, decarbonization efforts are underway in various regions to mitigate climate change, and carbon credits have begun to be issued for carbon storage through blue carbon.

[0004] The certification and issuance of carbon credits based on blue carbon requires an assessment of the amount of carbon dioxide (CO2) stored in the target marine area. As a convenient method for estimating the amount of CO2 stored in marine areas, the Wetland Guidelines created by the Intergovernmental Panel on Climate Change (IPCC) provide a procedure for calculating CO2 storage from the area and absorption coefficient of each type of seaweed bed. Methods proposed for measuring the area of ​​seaweed beds include using underwater cameras and satellite images. Absorption coefficients are classified according to the type of plant in the seaweed bed and are set based on the results of past surveys.

[0005] Meanwhile, one marine science method for assessing carbon storage in ocean areas is to calculate net ecosystem production (NEP), a value used to monitor the carbon balance at the ocean surface. NEP in an ocean area is defined as net primary production (the amount of carbon absorbed by photosynthesis by plants and algae minus the amount of carbon released through respiration) minus the amount of carbon released due to the death of plants and algae and the decomposition of organic matter released by plants and algae, and is calculated from measurements such as dissolved oxygen (DO) and water temperature. In an ocean area, a positive NEP indicates a state of carbon absorption, and a negative NEP indicates a state of carbon emission.

[0006] NEP varies both daily and seasonally. During clear days and in the summer when there is a lot of solar radiation, photosynthesis becomes active and net primary production exceeds the amount of carbon released through respiration and decomposition, resulting in a positive NEP. At night and in winter, NEP often becomes negative. This fluctuating NEP is calculated and evaluated as an annual balance. Estimating carbon storage through annual monitoring of NEP in marine areas may be able to provide a more realistic assessment of carbon storage than calculations using seaweed bed area and absorption coefficients, as it reflects the effects of each year's weather conditions.

[0007] Furthermore, the conservation of seaweed beds has the effect of maintaining and improving biological productivity and biodiversity in coastal areas by serving as fishing reefs inhabited by a variety of organisms. Seagrass also has the effect of protecting seawalls. These effects contribute to the conservation of the marine environment, so the conservation of seaweed beds and seagrass has significance beyond just absorbing and storing carbon. The organic matter produced by the primary production of plants and algae serves as food for zooplankton, which is then ingested by more advanced organisms, greatly affecting the marine ecosystem. For this reason, monitoring NEP is thought to provide useful information for maintaining and managing the environment and ecosystem of seaweed beds in a healthy state.

[0008] A method for measuring carbon balance in marine areas is disclosed, for example, in Patent Document 1. The technology disclosed in Patent Document 1 observes the partial pressure of carbon dioxide in seawater, and uses this partial pressure and pH to calculate the equilibrium of the carbonate system in seawater to calculate total alkalinity and total carbon dioxide in seawater, thereby determining inorganic carbon production and organic carbon production. The technology in Patent Document 1 reduces propagation errors by correcting pH electrode drift (changes in sensor response due to fouling of the reaction section, etc.), enabling long-term, automatic, continuous measurement of stored carbon volume.

[0009] A method for monitoring the health and abnormalities of marine areas is disclosed, for example, in Patent Document 2. The technology disclosed in Patent Document 2 selects a seawater sampling location from an image of the sea surface taken by an unmanned aerial vehicle, identifies the type of plankton that causes red tides from images of the seawater sampled by the unmanned aerial vehicle taken under a microscope, and counts the number of individuals of each type of plankton to identify harmful red tides. The technology in Patent Document 2 makes it possible to sample seawater, identify harmful red tides, and notify the results of the harmful red tide identification in a short period of time. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-4718 [Patent Document 2] Patent Publication No. 2021-71445 Summary of the Invention [Problem to be solved by the invention]

[0011] It is believed that continuous spatiotemporal measurement and monitoring of the carbon balance of marine areas is useful for evaluating carbon absorption and storage in seaweed beds and seaweed farms and for managing environmental conditions. However, continuous monitoring of NEP by measuring DO and other parameters in actual marine areas requires addressing various issues.

[0012] For example, coastal areas are prone to sudden events, such as sudden increases in river inflows due to heavy rainfall on land or wind stirring up bottom sediment, which can cause fluctuations in measured values ​​such as DO used to calculate NEP. Furthermore, changes in DO originating from sources other than seaweed and algae (for example, biodegradation of readily decomposable organic matter from land, open sea, and bottom sediment) must be excluded from the assessment of carbon storage by blue carbon. However, whether changes in DO are due to sources other than seaweed and algae must be determined on an ongoing basis, taking into account the complex environmental conditions of the marine area.

[0013] Furthermore, continuous measurements in the ocean are carried out in a harsh environment for measuring instruments, so they must be inspected and maintained at appropriate times. When monitoring seaweed beds, measuring instruments are installed at multiple locations across a wide ocean area, so performing regular maintenance on all of the measuring instruments is a significant burden. For this reason, it is preferable to perform maintenance according to the condition of each measuring instrument.

[0014] The technology described in Patent Document 1 observes the carbon dioxide partial pressure in seawater instead of DO to determine inorganic carbon production (IP) and organic carbon production (OP), which is thought to enable a more direct and accurate assessment of the carbon balance of marine areas than using NEP. However, this technology has the problem that it may over- or underestimate the actual carbon storage amount because it assesses carbon storage including increases and decreases in carbon dioxide due to factors other than seaweed.

[0015] The technology described in Patent Document 2 uses seawater samples collected by an unmanned aerial vehicle to identify harmful red tides. Because carbon balance fluctuates daily, it is desirable to sample and measure water at least once a day. However, this technology requires manual work to assess the environmental condition of the marine area, such as the presence or absence of red tides. Furthermore, depending on weather conditions, collecting seawater may be difficult, making it difficult to continuously monitor the environmental condition of the marine area every day.

[0016] The object of the present invention is to provide a coastal environment monitoring system that can assess the state of the coastal environment of a marine area, taking into account the influence of organisms other than plants (e.g., seaweed and phytoplankton) and algae (e.g., seaweed). [Means for solving the problem]

[0017] The coastal environment monitoring system according to the present invention comprises a measurement unit having a plurality of measuring instruments that measures the dissolved oxygen concentration in seawater at a plurality of measurement points in a sea area; a primary production calculation unit that calculates the primary production produced by photosynthesis in the sea area based on the dissolved oxygen concentration measured by the measurement unit; a primary production estimation unit that estimates the primary production under current conditions related to primary production using previously acquired data or a theoretical formula; an environmental state determination unit that determines the current environmental state of the sea area based on the primary production calculated by the primary production calculation unit and the primary production estimated by the primary production estimation unit using a predetermined sea area environmental state pattern; and a display unit that outputs the determination result of the environmental state determination unit. [Effects of the Invention]

[0018] According to the present invention, a coastal environmental monitoring system can be provided that can evaluate the state of the coastal environment of a marine area, taking into account the influence of things other than plants (e.g., seaweed and phytoplankton) and algae (e.g., seaweed). [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a block diagram showing the configuration of a coastal environment monitoring system according to a first embodiment of the present invention. [Figure 2] 1 is a block diagram showing the configuration of a coastal environment monitoring system including a carbon balance evaluation unit and an alarm transmission unit in a first embodiment. [Figure 3] FIG. 10 is a block diagram showing the configuration of a coastal environment monitoring system according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] The coastal environment monitoring system of the present invention can determine the carbon balance in coastal areas of the ocean (for example, seaweed beds and seaweed farms) by distinguishing between the effects of the activities of living organisms (particularly plants such as seaweed and phytoplankton, and algae such as seaweed) and the effects of factors other than the activities of living organisms (for example, the effects of river water inflow and waves caused by seasons, weather, and earthquakes). This makes it possible to evaluate the environmental state of the ocean area.

[0021] The environmental conditions of marine areas described below refer to the state of the marine environment and the conditions related to biological activity such as photosynthesis. The environmental conditions of marine areas include, for example, the amount of sunlight reaching the ocean, the amount of oxygen and carbon dioxide dissolved and released at the sea surface, the amount of nutrients, organic matter, and turbidity dissolved from the bottom mud, the density of seaweed and algae growth, and the presence or absence of red tides.

[0022] A coastal environment monitoring system according to an embodiment of the present invention will be described below with reference to the drawings. In the drawings used in this specification, identical or corresponding components are designated by the same reference numerals, and repeated description of these components may be omitted. [Example]

[0023] A coastal environment monitoring system according to a first embodiment of the present invention will be described with reference to FIGS.

[0024] Figure 1 is a block diagram showing the configuration of a coastal environment monitoring system according to this embodiment. The coastal environment monitoring system according to this embodiment includes a measurement unit 1, a primary production calculation unit 2, a primary production estimation unit 3, an environmental state determination unit 4, and a display unit 5, and can be configured using a computer.

[0025] The measurement unit 1 is equipped with multiple measuring instruments and measures the dissolved oxygen concentration in seawater, seawater temperature, etc. at multiple measurement points in the ocean, as well as wind speed, air pressure, and air temperature at sea, to obtain measurement data. For example, the measurement unit 1 is equipped with a dissolved oxygen concentration meter and measures the dissolved oxygen concentration in seawater with the dissolved oxygen concentration meter. The measurement unit 1 transmits the obtained measurement data to the primary production calculation unit 2.

[0026] The primary production calculation unit 2 calculates the current primary production in the ocean area (the time when the measurement unit 1 measured the dissolved oxygen concentration) based on the dissolved oxygen concentration measured by the measurement unit 1. Primary production is the amount of organic matter produced by photosynthesis of plants (e.g., seaweed and phytoplankton) and algae (e.g., seaweed).

[0027] The primary production estimation unit 3 uses previously acquired data or a theoretical formula to estimate the primary production that is expected to be obtained under current conditions, and estimates fluctuations in primary production (for example, fluctuation range and fluctuation pattern). These conditions are conditions related to primary production, which will be described later. The primary production estimated by the primary production estimation unit 3 is the primary production that is expected to be obtained when there is no influence from factors other than the activity of living organisms.

[0028] The environmental state determination unit 4 uses a preset marine area environmental state pattern to determine the current environmental state of the marine area based on the current primary production calculated by the primary production calculation unit 2 and the primary production estimated by the primary production estimation unit 3. The environmental state of a marine area fluctuates due to influences from factors other than biological activity (for example, influences caused by the season, weather, hours of sunshine, seawater temperature, dissolved oxygen concentration, tide level, ocean currents, sunlight intensity, and the presence or absence of earthquakes). Marine area environmental state patterns are various patterns that represent such fluctuations in the environmental state of a marine area, and are assumed in advance and set in the environmental state determination unit 4.

[0029] The display unit 5 outputs to a display device the determination result of the environmental state determination unit 4. The display unit 5 may be provided with a display device and output the determination result to the provided display device, or may be connected to a display device and output the determination result to the connected display device.

[0030] The measurement unit 1, the primary production calculation unit 2, the primary production estimation unit 3, and the environmental state determination unit 4 will be described in detail below.

[0031] The measurement unit 1 is fixed to equipment installed on the sea (for example, a measurement buoy or a wind power generation device) or mounted on a mobile body such as an ROV (remotely operated vehicle). The measurement unit 1 preferably acquires measurement data at multiple points in the vertical and horizontal directions. For example, in the depth direction (vertical direction) of the sea area, the measurement unit 1 preferably acquires measurement data at least in the surface and bottom layers of the sea area.

[0032] The environmental conditions of marine areas, particularly coastal areas, can be locally affected by factors such as the inflow of river water or rainwater, tides, stirring up of bottom mud, and stirring up of seawater by ships, etc. For this reason, it is preferable to obtain measurement data at multiple points in the vertical and horizontal directions.

[0033] For example, in the vertical direction, environmental conditions in the ocean, such as the amount of sunlight reaching the ocean, the amount of oxygen and carbon dioxide dissolved and released at the ocean surface, and the amount of nutrients, organic matter, and turbidity released from the bottom mud, change, and the conditions for biological activity such as photosynthesis change.In addition, in the horizontal direction, the conditions for biological activity such as photosynthesis change, for example, depending on the density of seaweed and other algae, the presence or absence of red tides, and the distance from nearby river mouths and sewage outfalls.

[0034] Therefore, by collecting measurement data at multiple positions in the vertical and horizontal directions, information can be obtained to calculate primary production in the ocean area.

[0035] The measurement unit 1 measures at multiple positions in the depth direction, for example, by the following methods: moving the detection part of the measuring instrument vertically, providing a detection part for each measurement position in the depth direction, or measuring seawater pumped up by a pump from multiple measurement positions in the depth direction at sea. If the measurement unit 1 is mounted on a mobile body, it is preferable that the measurement unit 1 be equipped with a GPS (Global Positioning System) receiver or the like, and simultaneously acquire data on the measurement position along with the measurement data measured by the measuring instrument.

[0036] The primary production calculation unit 2 uses any known method to calculate the primary production in the marine area using the dissolved oxygen concentration in the seawater measured by the measurement unit 1 and other data (e.g., seawater temperature, wind speed at the ocean surface, barometric pressure, and air temperature). The primary production calculation unit 2 can calculate the primary production in the marine area, for example, using the method proposed by Odum (1956) and Bott (1996) that uses dissolved oxygen concentration, or a method based on these methods. In the above method, the net primary production is calculated by subtracting the decrease in dissolved oxygen at night from the increase in dissolved oxygen during the day.

[0037] The primary production calculation unit 2 may use data input from outside the coastal environment monitoring system as data to calculate primary production, in addition to the data measured by the measurement unit 1. For example, the primary production calculation unit 2 may obtain data on wind speed, atmospheric pressure, and temperature from publicly available information about the sea area.

[0038] This method of calculating primary production assumes that the increase in dissolved oxygen during the day is due to photosynthesis, and the decrease at night is due to biological respiration. In reality, the amount of dissolved oxygen in the ocean fluctuates due to factors such as river water flowing in from land, seawater advected from the open sea, and bottom seawater with low dissolved oxygen concentrations. Bottom seawater mixes with surface seawater due to vertical stirring and mixing in the ocean caused by strong winds, etc. In other words, the actual amount of dissolved oxygen varies not only due to the activity of living organisms (especially plants and algae), but also due to factors other than biological activity.

[0039] In the following, the influence of living organisms (especially plants and algae) will be referred to as "biotic influences," and the influence of factors other than living organisms will be referred to as "abiotic influences." Biological influences are mainly the influence of photosynthesis and respiration. Abiotic influences are mainly the influence caused by seasons, weather, earthquakes, seawater temperature, and ocean currents.

[0040] With conventional technology, it is difficult to distinguish between biological and non-biological influences and calculate primary production in a marine area. The coastal environment monitoring system according to this embodiment includes a primary production estimation unit 3 that can distinguish between these influences and calculate primary production.

[0041] The primary production estimation unit 3 estimates the dissolved oxygen concentration and primary production at the measurement point when there is no influence of abiotic organisms. Primary production when there is no influence of abiotic organisms is the primary production produced by the activity of living organisms, i.e., by photosynthesis.

[0042] The primary production estimation unit 3 stores, as past data, data indicating the relationship between primary production values ​​at measurement points and values ​​of conditions related to primary production. This past data is data obtained when it is believed that there is no influence of abiotic factors, and is data obtained by past measurements. In other words, the past data indicates the conditions under which primary production values ​​obtained in the past when there is no influence of abiotic factors were obtained. There are various conditions related to primary production, including, for example, season, weather, hours of sunshine, seawater temperature, dissolved oxygen concentration, carbon dioxide concentration in seawater, tide level, ocean current, sunlight intensity, whether or not there has been an earthquake, and types of plants and algae.

[0043] Furthermore, the primary production estimation unit 3 acquires the current values ​​of conditions related to primary production from measurements by the measurement unit 1 and inputs from outside the coastal environment monitoring system.

[0044] Then, the primary production estimation unit 3 uses the values ​​of the conditions related to primary production in the past data and the values ​​of the conditions related to primary production at the current time to estimate the primary production at the measurement point (the current primary production) from the primary production in the past data. Specifically, the primary production estimation unit 3 determines the values ​​of conditions related to primary production in past data that match or can be considered to match the values ​​of conditions related to primary production at the current time, determines the conditions related to primary production that correspond to the determined values, determines the primary production volume under the determined conditions related to primary production using the past data, and estimates this primary production volume determined using the past data as the current primary production volume.

[0045] The primary production estimation unit 3 can also estimate the current primary production volume using the values ​​of the conditions related to primary production at the current time and a theoretical formula obtained by modeling primary production in the marine area. Such a theoretical formula is publicly known, and by using such a theoretical formula, the primary production volume can be estimated from the values ​​of the conditions related to primary production.

[0046] In this way, the primary production estimation unit 3 can estimate the primary production and dissolved oxygen concentration that would be obtained in the absence of abiotic influences. Furthermore, the primary production estimation unit 3 can estimate the fluctuations in primary production (for example, the fluctuation range and fluctuation pattern) that would be obtained in the absence of abiotic influences.

[0047] The primary production calculation unit 2 may use the measured value of carbon dioxide in seawater as data used to calculate primary production. The primary production calculation unit 2 can calculate primary production using the value of carbon dioxide in seawater using any known method. The primary production estimation unit 3 may use the measured value of carbon dioxide in seawater as data used to estimate primary production. The carbon dioxide concentration in seawater is included in the conditions related to primary production. The measurement unit 1 is equipped with a carbon dioxide sensor and measures carbon dioxide in seawater. The primary production calculation unit 2 and the primary production estimation unit 3 can use the value of carbon dioxide measured by this carbon dioxide sensor.

[0048] The environmental state determination unit 4 holds a list of marine environmental state patterns, and uses this list to determine the current environmental state of the marine area using the current primary production calculated by the primary production calculation unit 2 and the primary production in the absence of non-living influences estimated by the primary production estimation unit 3.

[0049] The marine area environmental state pattern is set in advance and stored in the environmental state determination unit 4. The marine area environmental state pattern records (A) the state of primary production calculated by the primary production calculation unit 2 and the state of primary production estimated by the primary production estimation unit 3, (B) the environmental state of the marine area estimated in the state recorded in (A), and (C) the preferred response to be taken in the environmental state recorded in (B), all linked to one another. Note that the estimated environmental state of the marine area in (B) also records the estimated state of the measuring instruments provided in the measurement unit 1.

[0050] The determination made by the environmental state determination unit 4 and examples of marine environmental state patterns will be described later.

[0051] When assessing carbon storage as blue carbon, it is necessary to exclude increases or decreases in primary production due to factors other than photosynthesis.

[0052] The coastal environment monitoring system according to this embodiment may include a carbon balance evaluation unit for separately determining the carbon balance at the sea surface and the carbon balance due to photosynthesis. Furthermore, the coastal environment monitoring system according to this embodiment may include an alarm transmission unit for transmitting and displaying an alarm.

[0053] Fig. 2 is a block diagram showing the configuration of a coastal environment monitoring system equipped with a carbon balance evaluation unit and an alarm transmission unit. The coastal environment monitoring system shown in Fig. 2 further includes a carbon balance evaluation unit 6 and an alarm transmission unit 7 in addition to the coastal environment monitoring system shown in Fig. 1.

[0054] The carbon balance evaluation unit 6 calculates the carbon balance of the ocean area by separating it into the balance at the ocean surface and the balance due to photosynthesis (carbon balance due to plants and algae) using the current primary production calculated by the primary production calculation unit 2 and the environmental state of the ocean area determined by the environmental state determination unit 4. The carbon balance evaluation unit 6 can calculate the carbon balance at the ocean surface and the carbon balance due to photosynthesis using any known method, such as measuring the amount of dissolved oxygen. By separating the carbon balance at the ocean surface from the carbon balance due to photosynthesis, the carbon balance evaluation unit 6 can more accurately calculate the amount of carbon stored.

[0055] The alarm issuing unit 7 issues and displays an alarm or guidance on the appropriate action to be taken based on the environmental state of the sea area determined by the environmental state determining unit 4. The alarm issuing unit 7 can be configured as a display device.

[0056] Below are shown examples of determinations made by the environmental state determination unit 4, examples of marine area environmental state patterns, and examples of the operations of the carbon balance evaluation unit 6 and the alarm transmission unit 7 for each pattern. As described above, in the marine area environmental state pattern, the primary production calculated by the primary production calculation unit 2 and the primary production estimated by the primary production estimation unit 3, the marine area environmental state estimated in this state, and the response that is preferable to take in this environmental state are recorded in association with each other.

[0057] Based on the sea area environmental state pattern, in the case of the situation shown in (A), the environmental state determination unit 4 determines that the current environmental state of the sea area is the environmental state shown in (B).

[0058] (Pattern 1) (A) Situation: Compared to the primary production estimated by the primary production estimation unit 3, the primary production calculated by the primary production calculation unit 2 or the dissolved oxygen concentration near the bottom layer measured by the measurement unit 1 is significantly smaller or has suddenly decreased, and within a specified period, a wind has blown with a wind speed equal to or greater than a specified value, or an earthquake with a seismic intensity equal to or greater than a specified value has occurred (the specified period, the specified wind speed, and the specified seismic intensity are values ​​that are arbitrarily determined in advance). (B) Estimated environmental conditions in the marine area: A large amount of readily degradable organic matter was temporarily introduced into the marine area from land, or a large amount of readily degradable organic matter was temporarily released from the bottom sediment of the marine area, and dissolved oxygen was consumed during the biodegradation of this readily degradable organic matter. (C) Response: When determining the carbon balance due to photosynthesis (carbon balance due to plants and algae), the carbon balance evaluation unit 6 excludes all or a predetermined percentage of the primary production volume for the period corresponding to pattern 1 from the annual cumulative primary production volume (the predetermined percentage is a value determined arbitrarily in advance). The carbon balance evaluation unit 6 may execute such a response, or may output it as guidance to the alarm transmission unit 7.

[0059] (Pattern 2) (A) Situation: The primary production estimation unit 3 estimated primary production from past data for the season when the plants and algae in the target seaweed bed or aquaculture farm were in their non-growth period. Therefore, the primary production estimated by the primary production estimation unit 3 is a small value even when the amount of solar radiation is high. On the other hand, the primary production calculated by the primary production calculation unit 2 is larger than the primary production estimated by the primary production estimation unit 3. (B) Estimated environmental conditions in the ocean: Phytoplankton is proliferating near the surface of the ocean. (C) Response: The alarm transmitter 7 issues an alarm to warn of red tide.

[0060] (Pattern 3) (A) Situation: The primary production estimated by the primary production estimation unit 3 is significantly different from the primary production calculated by the primary production calculation unit 2. Or, the fluctuation pattern of the primary production estimated by the primary production estimation unit 3 matches the pattern shown when the dissolved oxygen concentration meter provided in the measurement unit 1 drifts or breaks down. Or, the dissolved oxygen concentration value measured by the dissolved oxygen concentration meter is significantly different from the value in the past data used by the primary production calculation unit 2. Or, the fluctuation pattern of the dissolved oxygen concentration measured by the dissolved oxygen concentration meter matches the pattern shown when the dissolved oxygen concentration meter drifts or breaks down. (B) Estimated environmental state of the sea area: The dissolved oxygen concentration meter provided in the measurement unit 1 is drifting or has broken down. (The state of the dissolved oxygen concentration meter is not the environmental state of the sea area, but as mentioned above, the estimated state of the dissolved oxygen concentration meter is also recorded in the (B) Estimated Environmental State of the Sea Area in the sea area environmental state pattern.) (C) Response: The alarm transmitter 7 issues an alarm to notify the user that maintenance of the dissolved oxygen concentration meter is to be performed. When determining the carbon balance due to photosynthesis (carbon balance due to plants and algae), the carbon balance evaluation unit 6 excludes all or a predetermined percentage of the primary production volume for the period corresponding to pattern 3 from the annual cumulative primary production volume (the predetermined percentage is a value determined arbitrarily in advance). The carbon balance evaluation unit 6 may execute such a response, or may output the information as guidance to the alarm transmitter 7.

[0061] (Pattern 4) (A) Situation: Fluctuations in the dissolved oxygen concentration measured by the dissolved oxygen meter provided in the measurement unit 1 did not match the annual dissolved oxygen concentration pattern in which stratification weakens in winter, causing the bottom and surface seawater to mix and the dissolved oxygen concentration in the bottom layer to return to a predetermined value (the predetermined value of the dissolved oxygen concentration is a value arbitrarily determined in advance). Alternatively, fluctuations in primary production calculated by the primary production calculation unit 2 did not match fluctuations in primary production estimated by the primary production estimation unit 3 from this annual dissolved oxygen concentration pattern. (B) Estimated environmental conditions in the ocean: Due to the influence of abnormal weather, mixing of bottom and surface seawater (vertical mixing) did not occur. Alternatively, easily decomposable organic matter has settled to the bottom layer, and dissolved oxygen is being consumed by biodegradation. (C) Response: The alarm transmitter 7 transmits an alarm to notify that a low-oxygen water mass (anoxic water mass) has occurred near the bottom layer. (Pattern 5) (A) Situation: The primary production calculated by the primary production calculation unit 2 has decreased from a certain point in time in response to fluctuations in the primary production estimated by the primary production estimation unit 3. Alternatively, the primary production calculated by the primary production calculation unit 2 has fluctuated in the same way as the primary production estimated by the primary production estimation unit 3 at some of the multiple locations, but has fluctuated by smaller values ​​than the primary production estimated by the primary production estimation unit 3 at other locations. (B) Estimated environmental condition of the sea area: Plants or algae are being eaten away in the target sea area. (C) Response: The alarm transmission unit 7 transmits an alarm to notify that there is a possibility of predation damage occurring in the target sea area.

[0062] The marine environmental condition patterns will differ depending on the topography and ocean currents of the target sea area, and are also expected to change with environmental changes. For this reason, the patterns established based on past surveys should be updated or added to as needed based on surveys conducted in parallel with the use of the coastal environmental monitoring system of this embodiment, or on data obtained by this system.

[0063] As described above, the coastal environment monitoring system according to this embodiment can monitor primary production in marine areas to estimate and evaluate the state of the coastal environment of a marine area, and can accurately estimate the amount of carbon absorbed and stored in the marine area. Furthermore, by monitoring signs of red tides and predation damage and taking early countermeasures, and by monitoring the location and frequency of occurrence of hypoxic water masses, it is possible to monitor changes in the health of the marine area. [Example]

[0064] Second Embodiment A coastal environment monitoring system according to a second embodiment of the present invention will be described with reference to Fig. 3. In the following, differences between the coastal environment monitoring system according to the second embodiment and the coastal environment monitoring system according to the first embodiment will be mainly described.

[0065] 3 is a block diagram showing the configuration of a coastal environment monitoring system according to this embodiment. The coastal environment monitoring system according to this embodiment further comprises a carbon measurement unit 8 in addition to the components of the coastal environment monitoring system shown in FIG.

[0066] The carbon measurement unit 8 measures the concentration of dissolved carbon dioxide in seawater and the concentration of carbon dioxide in the gas phase at sea level using a carbon dioxide sensor to determine the carbon balance at the sea surface. The carbon measurement unit 8 can determine the carbon balance at the sea surface using any known method. For example, the carbon measurement unit 8 can determine the carbon balance at the sea surface based on the difference between the concentration of dissolved carbon dioxide in seawater and the concentration of carbon dioxide in the gas phase at sea level. Furthermore, the concentration of dissolved carbon dioxide in seawater and the concentration of carbon dioxide in the gas phase at sea level can be included in the conditions related to primary production.

[0067] The carbon balance evaluation unit 6 calculates the carbon balance of the ocean area by dividing it into the balance at the ocean surface and the balance due to photosynthesis (carbon balance due to plants and algae) using the carbon balance at the ocean surface calculated by the carbon measurement unit 8, the current primary production calculated by the primary production calculation unit 2, and the environmental state of the ocean area determined by the environmental state determination unit 4. As explained in Example 1, the carbon balance evaluation unit 6 can calculate the carbon balance at the ocean surface and the carbon balance due to photosynthesis by any known method.

[0068] Since the carbon dioxide concentration in the gas phase above the ocean fluctuates little, the carbon measurement unit 8 may use a predetermined constant value rather than a measured value as the carbon dioxide concentration in the gas phase above the ocean when calculating the carbon balance at the sea surface.

[0069] The carbon balance at the ocean surface determined by the carbon measurement unit 8 is a carbon balance that includes all influences on carbon balance, such as photosynthesis, transport from land and open sea, and elution from bottom sediments. For this reason, it is thought that the difference between the carbon balance determined by the carbon measurement unit 8 and the carbon balance determined by the carbon balance evaluation unit 6 in Example 1 (the carbon balance determined using the primary production calculated by the primary production calculation unit 2 and the environmental state of the ocean area determined by the environmental state determination unit 4) is mainly affected by increases and decreases in carbon dioxide due to factors other than photosynthesis, plants and algae, and steady-state respiration of organisms.

[0070] In this embodiment, the carbon balance evaluation unit 6 evaluates the carbon balance contributed by plants and algae, excluding this difference, so that the carbon balance evaluation unit 6 can more accurately determine the carbon balance and carbon storage amount.

[0071] As explained above, in the coastal environment monitoring system according to this embodiment, the primary production is evaluated using both the measurement results of the carbon balance at the sea surface by the carbon measurement unit 8 and the measurement results of the dissolved oxygen concentration by the measurement unit 1, thereby improving the accuracy of estimating the amount of carbon absorbed and stored in the sea area.

[0072] The present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to embodiments including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment. It is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to delete part of the configuration of each embodiment, or to add or replace other configurations. [Explanation of symbols]

[0073] 1...measuring unit, 2...primary production calculation unit, 3...primary production estimation unit, 4...environmental state determination unit, 5...display unit, 6...carbon balance evaluation unit, 7...alarm transmission unit, 8...carbon measurement unit.

Claims

1. a measuring unit that includes a plurality of measuring devices and measures the dissolved oxygen concentration in seawater at a plurality of measurement points in the sea area; a primary production calculation unit that calculates the amount of primary production produced by photosynthesis in the sea area based on the dissolved oxygen concentration measured by the measurement unit; a primary production amount estimation unit that estimates the primary production amount under current conditions related to primary production using previously acquired data or a theoretical formula; an environmental state determination unit that determines the current environmental state of the sea area based on the primary production calculated by the primary production calculation unit and the primary production estimated by the primary production estimation unit using a predetermined sea area environmental state pattern; a display unit that outputs the determination result of the environmental state determination unit; Equipped with A coastal environment monitoring system characterized by:

2. the data acquired in the past is past data indicating a relationship between the value of the primary production amount and the value of the condition related to the primary production, and includes at least a dissolved oxygen concentration; the primary production amount estimation unit estimates the current primary production amount from the primary production amount in the past data by using values ​​of conditions related to primary production in the past data and values ​​of conditions related to primary production at the current time; The coastal environment monitoring system according to claim 1 .

3. In the marine environmental state pattern, the primary production calculated by the primary production calculation unit, the state of the primary production estimated by the primary production estimation unit, and the environmental state estimated in the state are recorded in association with each other. The coastal environment monitoring system according to claim 1 .

4. Equipped with an alarm transmitter, The marine environmental state pattern further includes a correspondence that is preferable to be taken in the environmental state estimated in the situation, the correspondence being linked to the situation and the estimated environmental state, and the correspondence being recorded. the alarm issuing unit issues and displays the recommended response. The coastal environment monitoring system according to claim 3 .

5. the desired action includes performing maintenance on the measuring instrument; the alarm issuing unit issues an alarm informing the user that maintenance of the measuring instrument is to be performed; The coastal environment monitoring system according to claim 4.

6. the measuring unit includes a carbon dioxide sensor and measures carbon dioxide in seawater; the primary production amount calculation unit calculates the primary production amount using the carbon dioxide value measured by the carbon dioxide sensor; the primary production estimation unit estimates the primary production using the carbon dioxide value measured by the carbon dioxide sensor; The coastal environment monitoring system according to claim 1 .

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