Dynamical Behaviour of a Nutrient-Plankton Model with Holling Type IV, Delay, and Harvesting

<div>Variation of the optimal effort <svg height="8.68572pt" id="M584" style="vertical-align:-0.0498209pt" version="1.1" viewbox="-0.0498162 -8.6359 8.13765 8.68572" width="8.13765pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M593 650H142L136 622C219 616 224 611 209 531L130 120C114 39 108 34 23 28L17 0H501C518 32 557 130 568 158L540 169C519 132 495 93 469 70C439 43 409 35 332 35C272 35 241 37 225 50C211 61 211 89 222 149L253 320H350C441 320 443 312 441 239H471L510 434H481C455 366 448 358 360 358H260L303 572C311 613 312 615 348 615H431C509 615 522 603 532 581C544 555 546 531 545 491L574 493C583 555 592 631 593 650Z"></path></g></svg> with respect to time with different <svg height="6.1673pt" id="M585" style="vertical-align:-0.2063904pt" version="1.1" viewbox="-0.0498162 -5.96091 6.40217 6.1673" width="6.40217pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M471 456L444 459C426 433 414 430 388 430C324 430 270 434 216 434C103 434 51 374 23 338L43 317C96 366 146 380 221 375L154 109C149 86 147 68 147 52C147 4 168 -12 197 -12C240 -12 291 25 334 71L320 96C295 75 268 58 252 58C238 58 227 79 238 138C251 211 272 296 292 372C310 372 332 368 350 368C391 368 421 369 434 371C444 388 455 413 471 456Z"></path></g></svg> in system (<a href="https://static.hindawi.com/articles/ddns/volume-2018/9232590/figures/#EEq2">2</a>).</div>

Discrete Dynamics in Nature and Society

fig8

Figure 8

Figure 8: Dynamical Behaviour of a Nutrient-Plankton Model with Holling Type IV, Delay, and Harvesting 