title: The role of the deposit feeding bivalve Macomona liliana in a simple biophysical model for predicting estuarine ecosystem tipping points

authors: Thomson, Taylor Scott

subjects: Macomona liliana

abstract: Estuaries are highly productive, coastal marine environments that provide vital ecosystem functions supporting human health. Throughout history, many major settlements have been established adjacent to estuaries, so to take advantage of the resources they provide. After centuries of exploitation and heavy pollution, the health of estuaries have experienced a notable decline. The need for effective management strategies has arisen, but their efficacy continues to be questioned due to the dynamic and unpredictable nature of these environments. Non-linear processes, such as regime shifts, make long-term predictions of ecosystem health a point of concern. To combat this issue in New Zealand, ecosystem interaction networks (EINs) have been used to predict the future health of estuaries using long-term statistical modelling. Unfortunately, these models fail to capture the coupling interactions between biotic and abiotic variables that occur in such a volatile environment. Therefore, we have created a simple model design that replicates the dynamic ecosystem interactions found within the benthic environments of New Zealand estuaries, with a specific focus on the behaviour of the keystone bivalve species Macomona liliana. A multitude of biophysical dynamical models currently exist in this field (e.g. Delft3D and DELWAQ); however none with the ability to replicate the exchange of nutrients between the sediment and benthic layer caused by M. liliana pumping behaviour. Consequently, this makes our model the first of its kind. Our model design simulates the variation of three dynamic variables (biomass, nutrients, detritus) corresponding to the interactions of M. liliana and microphytobenthos (MPB) at a representative site of New Zealand sandy bottom estuaries (Tuapiro Point, Tauranga Harbour). Extensive testing was conducted to ensure that, at the baseline level, the model’s output was consistent with field sampling data seen within the literature. Once completed, the model was tested against external forcing factors that are likely to occur within New Zealand estuaries – turbidity, sedimentation, and external nutrient loading. We found that our system is light limited, with M. liliana and MPB biomasses both declining with increasing turbidity. MPB populations fluctuate significantly following a sediment mud content increase, which we believe demonstrates a reaction to an ecological tipping point being surpassed. Furthermore, we found that a significant influx of external nutrient loading is required to initiate a MPB bloom, which the system cannot maintain despite nutrient levels remaining high. Our model’s results are in agreement with estuarine responses seen in the past, with our design exceeding the guidelines surrounding the efficacy in predicting ecosystem tipping points. Therefore, due to its unique ability to demonstrate the interactions within coupled systems and its broad applicability globally, we believe our model can become a central component of future estuarine management strategies. Recommendations are made for future improvements to the model design, increasing both its range of simulated ecological processes and the validity of its predictions.

text: The role of the deposit feeding bivalve Macomona liliana in a simple biophysical model for predicting estuarine ecosystem tipping points Estuaries are highly productive, coastal marine environments that provide vital ecosystem functions supporting human health. Throughout history, many major settlements have been established adjacent to estuaries, so to take advantage of the resources they provide. After centuries of exploitation and heavy pollution, the health of estuaries have experienced a notable decline. The need for effective management strategies has arisen, but their efficacy continues to be questioned due to the dynamic and unpredictable nature of these environments. Non-linear processes, such as regime shifts, make long-term predictions of ecosystem health a point of concern. To combat this issue in New Zealand, ecosystem interaction networks (EINs) have been used to predict the future health of estuaries using long-term statistical modelling. Unfortunately, these models fail to capture the coupling interactions between biotic and abiotic variables that occur in such a volatile environment. Therefore, we have created a simple model design that replicates the dynamic ecosystem interactions found within the benthic environments of New Zealand estuaries, with a specific focus on the behaviour of the keystone bivalve species Macomona liliana. A multitude of biophysical dynamical models currently exist in this field (e.g. Delft3D and DELWAQ); however none with the ability to replicate the exchange of nutrients between the sediment and benthic layer caused by M. liliana pumping behaviour. Consequently, this makes our model the first of its kind. Our model design simulates the variation of three dynamic variables (biomass, nutrients, detritus) corresponding to the interactions of M. liliana and microphytobenthos (MPB) at a representative site of New Zealand sandy bottom estuaries (Tuapiro Point, Tauranga Harbour). Extensive testing was conducted to ensure that, at the baseline level, the model’s output was consistent with field sampling data seen within the literature. Once completed, the model was tested against external forcing factors that are likely to occur within New Zealand estuaries – turbidity, sedimentation, and external nutrient loading. We found that our system is light limited, with M. liliana and MPB biomasses both declining with increasing turbidity. MPB populations fluctuate significantly following a sediment mud content increase, which we believe demonstrates a reaction to an ecological tipping point being surpassed. Furthermore, we found that a significant influx of external nutrient loading is required to initiate a MPB bloom, which the system cannot maintain despite nutrient levels remaining high. Our model’s results are in agreement with estuarine responses seen in the past, with our design exceeding the guidelines surrounding the efficacy in predicting ecosystem tipping points. Therefore, due to its unique ability to demonstrate the interactions within coupled systems and its broad applicability globally, we believe our model can become a central component of future estuarine management strategies. Recommendations are made for future improvements to the model design, increasing both its range of simulated ecological processes and the validity of its predictions.

year: 2022

title: Benefit sharing: Why inclusive provenance metadata matter

authors: Golan, J

abstract: Fair and equitable benefit sharing of genetic resources is an expectation of the Nagoya Protocol. Although the Nagoya Protocol does not yet formally apply to Digital Sequence Information (“DSI”), discussions are currently underway regarding to include such data through ongoing Convention on Biological Diversity (“CBD”) negotiations. While Indigenous Peoples and Local Communities (“IPLC”) expect the value generated from genomic data to be subject to benefit sharing arrangements, a range of views are currently being expressed by Nation States, IPLC and other stakeholders. The use of DSI gives rise to unique considerations, creating a gray area as to how it should be considered under the Nagoya Protocol’s Access and Benefit Sharing (“ABS”) principles. One way for benefit sharing to be enhanced is through the connection of data to proper provenance information. A significant development is the use of digital labeling systems to ensure that the origin of samples is appropriately disclosed. The Traditional Knowledge and Biocultural Labels initiative offers a practical option for data provided to genomic databases. In particular, the BioCultural Labels (“BC Labels”) are a mechanism for Indigenous communities to identify and maintain provenance, origin and authority over biocultural material and data generated from Indigenous land and waters held in research, cultural institutions and data repositories. This form of cultural metadata adds value to the research endeavor and the creation of Indigenous fields within databases adds transparency and accountability to the research environment.

text: Benefit sharing: Why inclusive provenance metadata matter Fair and equitable benefit sharing of genetic resources is an expectation of the Nagoya Protocol. Although the Nagoya Protocol does not yet formally apply to Digital Sequence Information (“DSI”), discussions are currently underway regarding to include such data through ongoing Convention on Biological Diversity (“CBD”) negotiations. While Indigenous Peoples and Local Communities (“IPLC”) expect the value generated from genomic data to be subject to benefit sharing arrangements, a range of views are currently being expressed by Nation States, IPLC and other stakeholders. The use of DSI gives rise to unique considerations, creating a gray area as to how it should be considered under the Nagoya Protocol’s Access and Benefit Sharing (“ABS”) principles. One way for benefit sharing to be enhanced is through the connection of data to proper provenance information. A significant development is the use of digital labeling systems to ensure that the origin of samples is appropriately disclosed. The Traditional Knowledge and Biocultural Labels initiative offers a practical option for data provided to genomic databases. In particular, the BioCultural Labels (“BC Labels”) are a mechanism for Indigenous communities to identify and maintain provenance, origin and authority over biocultural material and data generated from Indigenous land and waters held in research, cultural institutions and data repositories. This form of cultural metadata adds value to the research endeavor and the creation of Indigenous fields within databases adds transparency and accountability to the research environment.

year: 2022

title: Haere mai rā

authors: Maxwell, Te Kahautu

abstract: Whakaeke (entrance). Lyrics composed by Te Kahautu Maxwell, Musical score composed by Te Whānau Mitai. Performed by Ōpōtiki Mai Tawhiti (Kapa Haka group) (3mins)

Waiata Tira: Aroha
Whakaeke: Haere mai rā
Mōteatea: Te Pātere a Te Turuki
Poi: Iarararararī
Waiata ā ringa: Taku Mana Māori Motuhake
Haka: Waiwharangi
Whakawātea: Āio

text: Haere mai rā Whakaeke (entrance). Lyrics composed by Te Kahautu Maxwell, Musical score composed by Te Whānau Mitai. Performed by Ōpōtiki Mai Tawhiti (Kapa Haka group) (3mins)

Waiata Tira: Aroha
Whakaeke: Haere mai rā
Mōteatea: Te Pātere a Te Turuki
Poi: Iarararararī
Waiata ā ringa: Taku Mana Māori Motuhake
Haka: Waiwharangi
Whakawātea: Āio

year: 2020