Spyvalve chronicles daily: Update for Mediterranean Mussels at ManMarina on 2025-09-18

Harry Butler Institute, Murdoch University, Perth, Western Australia

\(\\\) To cite this article: Cottingham A, Beatty S, Tweedley J. (2025). Spyvalve chronicles daily: Update for Mediterranean Mussels at ManMarina on 2025-09-17. Spyvalve Repositories, Vol. 1.

Spyvavle chronicles daily for ManMarina provides updates on weather and bivalve (Agents) activity for the previous 24h period (from midnight). The report provides information on data aquisition, number of active agents (individuals providing sufficient data), and valve gaping activities, incuding average activity, amount of time valves remained closed, number of full and micro-closures and synchronised closing events.

\(\\\) Monitoring station location.

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Weather conditions

The following weather report is autogenerated based on data obtained from the Bureau of Meteorology for Mandurah. The contents of this report have not undergone rigorous assessment and thus care must be taken when drawing conclusions.

Air temperatures recorded at Mandurah ranged from 13 to 19.1 degrees C. Total rainfall was 3.2 mm. Humidity ranged from 50 to 86% (Fig.1). Maximum wind speed was 20 km/h (Fig.2).

Figure 1. Weather conditions recorded for Mandurah.

Figure 2. Wind conditions (direction and speed) recorded at Mandurah.

Data records for last day

WARNING. This report is autogenerated daily for data collected at ManMarina. The contents of this report have not undergone rigorous assessment. Care must be taken when drawing conclusions from the following analyses.

Figure 1. Approximate frequency of data records received by the network. This represents ~100 % of possible records for this station.

There were 7 active agents sending data (Table 1). These are based on the difference between the minimum and maximum mV values for each Agent, with a minimum difference of 10 mV being sufficient to deem those data relaible. Unreliable Agents are removed from analyses. Over the day percentage open ranged from 48 to 97 %. The number of closures for the day ranged from 12 to 46 and the number of micro-closures from 26 to 214. The maximum time all mussels closed at once was 1 minutes.

	Active	Min (mV)	Max(mV)	Diff(mV)	% open	n closures	n micro-closures
A000	Active	440	470	30	80	12	26
A001	Active	463	482	19	77	46	77
A002	Down	0	3	3	NA	NA	NA
A003	Active	454	478	24	72	28	61
A004	Active	328	504	176	97	34	214
A005	Active	334	443	109	61	21	36
A006	Active	527	609	82	48	26	35
A007	Active	513	569	56	64	21	41

Mean of shell gaping activity

Figure 4. Average of mussel gape activity recorded for 7 relaible agents. Data were transformed, with values of 1.0 corresponding to shells being open to their greatest extent and values <0.2 (red-dashed line) considered as shell being closed

Shell closures by the hour

Figure 5. Number of closures and total time each agent spent closed.

Figure 6. Transformed mussel gape activity for the 7 relaible agents and water temperature at ManMarina.

Appendix

Appendix 1. Raw valve gape activity for ManMarina.